Building in the AWS Cloud offers significant advantages in agility and scalability. The cloud allows companies to provision resources in minutes, enabling them to experiment and launch new projects, like a mobile app, much faster than with traditional on-premises procurement cycles. This directly addresses the benefit of increased speed. Furthermore, AWS provides elasticity, allowing the application's infrastructure to automatically scale up to handle increases in user traffic as it becomes popular. This eliminates the need to pre-purchase and over-provision hardware, ensuring performance is maintained while costs are aligned with actual usage. These two benefits—speed and elasticity—are core value propositions of the AWS Cloud.

A. This describes an on-premises model, which requires large upfront capital expenditure (CapEx). The AWS Cloud model trades CapEx for variable operational expenditure (OpEx).
C. AWS manages the physical security of its data centers as part of the AWS Shared Responsibility Model. Customers do not have control over the physical infrastructure.
E. While users can select an AWS Region and Availability Zone (AZ), they cannot choose the specific, individual data center building where their application servers will be hosted. ---

1. AWS Whitepaper

"The Six Advantages of Cloud Computing": This document outlines the core benefits of cloud.

For Answer B (Speed/Agility): Under the heading "Increase speed and agility

" it states

"The time it takes to make those resources available to your developers is reduced to minutes."

For Answer D (Scalability): Under "Stop guessing capacity

" it explains

"You can access as much or as little capacity as you need

and scale up and down as required with only a few minutes’ notice."

For Incorrect Answer A (Cost Model): Under "Trade capital expense for variable expense

" it states

"Instead of having to invest heavily in data centers and servers... you can pay only when you consume computing resources."

2. AWS Documentation

"Shared Responsibility Model": This page clarifies security duties.

For Incorrect Answer C (Physical Security): The documentation shows that "Physical security of data centers" is an AWS responsibility under "Security of the Cloud."

3. AWS Documentation

"Regions and Zones": This explains the global infrastructure hierarchy.

For Incorrect Answer E (Data Center Selection): The section "Availability Zones" states

"An AZ is one or more discrete data centers... AWS customers can choose their Regions and their AZs

but they cannot choose a specific data center within an AZ."