Because the existing CMS cannot run unchanged in a cloud environment, “lift-and-shift” (Rehost) is not feasible.
1. Repurchase (C) lets the company swap the self-hosted CMS for a SaaS or marketplace-licensed CMS that is already cloud-native; this incurs very little engineering work.
2. Replatform (D) involves making only small configuration or runtime changes—​for example, moving the CMS database to Amazon RDS or replacing local storage with Amazon EFS—​so the application can operate in AWS without code change. Both approaches achieve migration with the least development effort among the viable strategies.

A. Retire – Eliminates the application instead of migrating it; does not satisfy the requirement to keep the CMS.
B. Rehost – Requires the workload to run unmodified; the audit shows it is incompatible, so this option fails.
E. Refactor – Demands substantial code redesign; highest cost and effort, contrary to “least effort.”

1. AWS Prescriptive Guidance

“Migration Strategy Best Practices – The 7 Rs

” section 2.3

tables “Repurchase” and “Replatform” (2022-10-28).

2. AWS Whitepaper “Migrating Your Existing Applications to the AWS Cloud

” pp. 6-8 (Replatform: ‘Lift-tinker-and-shift’; Repurchase: ‘Move to SaaS’).

3. Amazon Web Services

“AWS CAF: Application Portfolio Assessment

” Step 3

para 4 (Repurchase requires only licensing change; minimal technical effort).

4. University of Maryland Cloud Computing Course (CMSC 498O)

Lecture 12 slides 15-18 (7 Rs matrix—Repurchase and Replatform ranked lowest engineering effort after simple rehost).