To implement a custom SOAP web service in Apex, the class must be declared with the global access modifier. Methods that are intended to be exposed to external applications via the WSDL must be declared as both global and static, and they must use the webservice keyword.

Helper methods, which are for internal use within the class and should not be exposed in the WSDL, must be defined without the webservice keyword. Option D correctly follows this structure by defining a global class, a webservice global static method for external access, and a public helper method that remains internal to the Salesforce organization.

1. Salesforce Apex Developer Guide

"Apex Web Services":

Section: Defining Apex Web Service Methods: "To expose an Apex method as a web service

the method must be global static and be part of a global class. The webservice keyword must be used for any method that should be exposed." This directly supports why Option D is correct and why options A and C are incorrect.

Section: webservice Keyword: This section details the syntax and requirements

reinforcing that a webservice method must be global and static within a global class for SOAP services. This confirms why Option B is incorrect

as it lacks the necessary keyword for exposure.

2. Trailhead by Salesforce

"Apex Integration Services" Module:

Unit: Apex Web Services: "To expose an Apex class and methods so that external applications can access your code and your application

you must use the webservice and global keywords." This module provides examples that align with the structure shown in Option D

where the class is global and the exposed method is webservice static. It clarifies that methods without the webservice keyword are not exposed.

The requirements necessitate a one-to-many relationship where one Opportunity can have multiple EngineeringSupportc records. This means the relationship field must be created on the EngineeringSupportc object (the "many" side) and point to the Opportunity object (the "one" side). The second requirement, to show aggregate information (e.g., count, sum) from the child EngineeringSupportc records on the parent Opportunity record, is a direct feature of Master-Detail relationships via Roll-Up Summary Fields. A Lookup relationship does not natively support this aggregation capability. Therefore, a Master-Detail field from EngineeringSupportc to Opportunity is the correct implementation.

1. Salesforce Help: Object Relationships Overview. This document explicitly states

"Use a master-detail relationship to... create roll-up summary fields on the master record that aggregate the detail records." This directly addresses the aggregation requirement.

2. Salesforce Help: Create a Master-Detail Relationship. This guide clarifies the implementation: "A relationship field (which is a custom field) is created on the detail object." In this scenario

EngineeringSupportc is the detail object.

3. Salesforce Developer Guide: Relationships Among Objects. This guide differentiates the relationship types

noting that a key feature of Master-Detail relationships is that they "allow you to define roll-up summary fields." It contrasts this with Lookup relationships

which lack this capability.

In Apex, a class uses the implements keyword to declare that it will provide the implementation for a specific interface. An interface defines a set of method signatures (a contract), and any class that implements the interface must provide a concrete implementation for all of those methods. The syntax public class ClassName implements InterfaceName is the standard and correct way to establish this relationship, ensuring the class adheres to the contract defined by the interface.

1. Apex Developer Guide

"Interfaces" Chapter: This guide explicitly states

"To implement an interface

use the implements keyword in the class declaration." It provides the syntax public class MyClass implements MyInterface { ... } as the correct format. (Salesforce

Apex Developer Guide

"Interfaces"

Syntax section).

2. Apex Developer Guide

"Using the extends Keyword" Section: This section clarifies that extends is used for class inheritance. It states

"A class can only extend one other class

but it can implement more than one interface." This directly contrasts the purpose of extends with implements. (Salesforce

Apex Developer Guide

"Classes"

"Using the extends Keyword" subsection).

In the Salesforce Aura Components framework, which follows a publish-subscribe pattern for events, an application event is fired using the fire() method. A component first gets an instance of the event using $A.get("e.namespace:eventName"). After optionally setting parameters on the event instance using setParams(), the component calls the fire() method on that instance. This action broadcasts the event to all components that have a registered handler for it.

1. Salesforce Aura Components Developer Guide

"Firing Application Events": The official documentation explicitly demonstrates firing an application event. The example code shows getting the event and then calling the fire() method on the event object.

Reference: In the section on Application Events

the guide states: "To fire an application event

you get an instance of the event in JavaScript and call fire() on it." The accompanying code example is: appEvent.fire();.

2. Salesforce Aura Components Developer Guide

"Component Events": The same fire() method is used for component events

reinforcing its role as the standard event-firing mechanism in the framework.

Reference: The "Firing Component Events" section provides a similar pattern: "Get an instance of the event by name... Fire the event by calling fire() on your event instance."

The Developer Console is the primary integrated development environment (IDE) for Salesforce developers. After executing tests, the "Tests" tab provides immediate and detailed feedback. The "Overall Code Coverage" panel within this tab aggregates the results and allows a developer to see the specific coverage percentage for each class involved in the test run. This panel is the most direct and feature-rich tool for analyzing coverage results, as it also allows for drilling down to see line-by-line coverage details.

1. Apex Developer Guide: In the "Testing Apex" chapter

under the section "Run Unit Tests and See Code Coverage

" it states

"After the test run finishes

you can view code coverage information in the Tests tab in the Developer Console. The Overall Code Coverage panel shows the code coverage percentage for every Apex class in your organization that has been included in the test run." (Salesforce

Apex Developer Guide

"Run Unit Tests and See Code Coverage").

2. Salesforce Help Documentation: The article "Check Your Code Coverage" explicitly instructs

"To view code coverage in the Developer Console

run your tests... After the tests run

you see the overall code coverage in the Overall Code Coverage pane of the Tests tab." (Salesforce Help

Article 000387317

"Check Your Code Coverage").

3. Trailhead - Apex Testing Module: The "Run Apex Tests" unit demonstrates the standard workflow: run tests

then navigate to the Developer Console's "Tests" tab to view the results in the "Overall Code Coverage" panel. This reinforces it as the standard developer practice. (Trailhead

Apex Testing

"Run Apex Tests").

To ensure tests are self-contained and have access to necessary records, data must be created within the test's transaction context.

A Test Data Factory (A) is a best-practice pattern that uses a dedicated Apex class to programmatically create and insert required sObject records. This approach promotes reusable, maintainable, and easy-to-understand test setups.

For large data volumes, as specified by the "500 records," the Test.loadData() method (C) is the most efficient and recommended approach. It populates records by reading from a CSV file stored as a static resource, bypassing per-transaction DML limits and simplifying the setup for extensive, static datasets.

1. Apex Developer Guide

"Creating Test Data for Apex Tests": This section explicitly details the two primary methods for creating test data. It describes using a "test utility class" (a Test Data Factory) for reusable data creation and the Test.loadData method for loading large sets of records from a static resource.

Quote/Concept: "A more useful and reusable method for creating test data is to use a test utility class... For some scenarios

you need to load a large set of data... You can do so by using the Test.loadData method."

2. Apex Developer Guide

"Isolation of Test Data from Organization Data in Unit Tests": This section explains that tests run in isolation by default and explicitly warns against using @IsTest(SeeAllData=true).

Quote/Concept: "Using @IsTest(SeeAllData=true) isn’t a best practice because it turns off data isolation for your tests and can make them harder to maintain and deploy."

3. Apex Developer Guide

"Enforcing Sharing Rules": This section defines the purpose of the with sharing and without sharing keywords

clarifying that their function is related to record-level security

not test data isolation.

Quote/Concept: "The with sharing or without sharing keywords specify the sharing mode for a class." This confirms its irrelevance to making data visible to a test.

To enforce object-level security and verify if the current user has permission to delete an Account record, the developer should use the isDeletable() method from the DescribeSObjectResult class. The most direct and standard way to access this for the Account object is by using the Schema.sObjectType.Account token. The expression Schema.sObjectType.Account.isDeletable() returns true if the running user has the "Delete" permission on the Account object as defined in their profile or permission sets, and false otherwise. This check should be performed before executing the DML delete operation to prevent exceptions and enforce security.

1. Apex Developer Guide

"Enforcing Object and Field Permissions": This section explicitly demonstrates using Schema.sObjectType tokens to check for user permissions. The guide states

"You can verify a user’s access to sObjects by calling the isAccessible

isCreateable

isDeletable

isUndeletable

or isUpdateable methods on DescribeSObjectResult." An example provided is if (Schema.sObjectType.Contact.isDeletable()) { ... }

which directly supports option B as the standard practice.

2. Apex Developer Guide

"DescribeSObjectResult Class": The documentation for the isDeletable() method specifies that it "Returns true if the current user can delete records of this object

false otherwise." It is a method of the DescribeSObjectResult class

which is obtained via a describe call (e.g.

Account.sObjectType.getDescribe() or the shortcut Schema.sObjectType.Account).

3. Salesforce Platform Developer I Certification Study Guide

"Data Security": This guide emphasizes the importance of using describe methods to check for object and field-level security (FLS) before performing DML operations to build secure applications. The use of Schema.sObjectType.YourObject.isDeletable() is a core concept for this security enforcement.

To create a constant whose value cannot be changed, the final keyword must be used. A final variable can only be assigned a value once, either in its declaration or within a constructor. Using the static keyword makes the variable associated with the class itself, rather than with a specific instance of the class, which is the standard convention for defining constants. Therefore, static final is the correct and most precise declaration to ensure the DELIVERYMULTIPLIER value remains constant throughout the application's execution and is accessible at the class level.

1. Apex Developer Guide

"Final Variables": "Use the final keyword to declare a constant. A final variable can only be assigned a value once

either in the declaration itself

or in an init method or constructor." This directly supports the use of final to meet the requirement that the value should not change.

2. Apex Developer Guide

"Static and Instance Methods

Variables

and Initialization Code": "Static variables are associated with a class... All instances of the same class share a single copy of the static variables." This supports using static for a value that should be singular and class-wide

which is characteristic of a constant.

3. Apex Developer Guide

"Variable Declaration": This section outlines the syntax for declaring variables

showing that static and final are access modifiers that precede the data type

confirming the structure static final decimal ....

To manage a resource-intensive Apex method, a developer must proactively monitor governor limit consumption and control the transaction's state. The System.Limits class provides methods like getCpuTime() and getLimitCpuTime(), which allow the code to check its resource usage mid-execution and take preventative action to avoid hitting governor limits. For transaction control, creating a Savepoint with Database.setSavepoint() establishes a point to which the transaction can be rolled back using Database.rollback(). This ensures that if an error occurs during the complex operation, the database can be returned to a consistent state, thus preserving data integrity. These two techniques directly address the dual requirements of avoiding governor limits and ensuring transaction control.

1. System.Limits Class: The Apex Developer Guide explains that the Limits class methods can be used to "check a specific governor limit against the limit for that governor." This is the standard practice for monitoring consumption within a transaction.

Source: Salesforce Apex Developer Guide

"Execution Governors and Limits"

Section: "Checking Governor Limit Consumption".

2. Database.Savepoint and Rollback: The Apex Developer Guide details transaction control

stating

"You can set a savepoint

which is a point in the request that you can roll back to... All DML operations that occurred after the savepoint are rolled back."

Source: Salesforce Apex Developer Guide

"Database Class"

Section: "Transaction Control".

3. @ReadOnly Annotation Restriction: The documentation for Apex annotations explicitly states

"A method defined with the @ReadOnly annotation can't perform DML operations."

Source: Salesforce Apex Developer Guide

"Apex Annotations"

Section: @ReadOnly.

4. Partial DML Statements: The documentation describes the allOrNone parameter for Database methods

which allows for partial success of a DML operation. This is distinct from managing the entire transaction's state with savepoints.

Source: Salesforce Apex Developer Guide

"Database Class"

Section: "DML Operations".

The question likely contains a typographical error, intending to ask about LimitException instead of LinkException. A LimitException is a special type of exception in Apex that cannot be caught using a try-catch block. When a governor limit (such as the total number of SOQL queries or maximum CPU time) is exceeded, the Apex runtime engine throws a LimitException. This immediately halts the current transaction and rolls back all operations, preventing any further code, including catch blocks, from executing. This behavior ensures that no single transaction can monopolize shared resources on the multitenant platform.

1. Salesforce Apex Developer Guide

"Exception Class and Built-In Exceptions": The documentation explicitly states

"Some exceptions can’t be caught

such as a LimitException that is thrown by the system when a governor limit has been exceeded. This type of exception is associated with the System.LimitException class."

2. Salesforce Apex Developer Guide

"Execution Governors and Limits": This section details the various governor limits. When any of these limits are surpassed

"the associated governor issues a runtime exception that cannot be handled (LimitException)." This confirms the uncatchable nature of the exception and its direct link to governor limits.

3. Salesforce Apex Developer Guide

"try-catch-finally Statements": This section describes how to handle exceptions that can be caught

providing examples for DmlException (the parent class for NoAccessException) and other standard exceptions

implicitly differentiating them from uncatchable exceptions like LimitException.