It will best for Sara to use PaaS as a service delivery model as it will provide multiple hosting environments, PaaS Key characteristics are:
- Support multiple languages and frameworks
- Multiple hosting environments
- Flexibility(plugins)
- Allow choice and reduce lock-in
- Ability to auto-scale

This is false. Please read the question carefully.
Question: is asking
On Demand "Shelf" Service where the correct characteristic is "0n Demand Self Service"

Artifacts are the logs, documentation, and other materials needed for audits and compliance; they are the evidence to support compliance activities. Both providers and customers have responsibilities for producing and managing their respective artifacts.
Reference: CSA Security GuidelinesV.4(reproduced here for the educational purpose)

lS0 27005 'provides guidelines for information security risk management' and 'supports the general concepts specified in ISO/IEC 27001 and is designed to assist the satisfactory implementation of information security based on a risk management approach.'