A Business Logic (BL) module's primary purpose is to encapsulate and isolate complex business rules, processes, or orchestrations. It composes functionality by consuming actions from one or more Core Services (CS) modules. This architectural pattern is used to manage complexity by creating a separate, reusable component for business logic that can have its own development lifecycle, independent of the core data model or the user interface that consumes it. This promotes reusability and simplifies maintenance.

A. This describes a specific implementation pattern (a Calculation Engine) for a BL module, not its fundamental purpose. A BL module is a broader concept.

B. This describes synchronization logic. While it could be implemented in a BL, it's more commonly placed in a Library (LIB) or Integration (IS) module to keep Core Services agnostic.

D. This is the definition of a Core Services (CS) module, which owns and exposes the application's core data model (entities) and basic data manipulation actions.

E. This describes an API wrapper, which is a consumer module, typically in the End-User layer, responsible for exposing functionality to external systems, not for encapsulating the business logic itself.

1. OutSystems Official Documentation

"Designing the architecture of your OutSystems applications

" Section: Core Services Layer. This section details the different types of modules. It states

"Business Logic modules (BL) implement business logic or processes. They are used to orchestrate the consumption of several Core Services

composing them to implement a more complex business operation. They can also be used to isolate a very complex piece of logic... that has its own life cycle." This directly supports option C and clarifies why A is only a specific example.

2. OutSystems Official Documentation

"The 4-Layer Canvas

" Section: Core Layer. This document illustrates the architectural layers and module responsibilities. It places BL modules in the Core Layer

distinct from CS modules (refuting D) and showing them as providers of logic to be consumed by upper layers

not as API wrappers themselves (refuting E).

3. OutSystems Training

"Architecture Specialization Courseware

" Module: Core Services. The course materials explicitly define a BL module's role as orchestrating and composing logic from CS modules to avoid complex logic from being duplicated in consumer modules (e.g.

UI modules). This reinforces the concept of isolation and composition described in option C.