Which setup should a Solution Architect propose to support this development approach considering costs and data segregation?

A company actively uses CI/CD processes for its Service Cloud implementation and is adding Marketing Cloud and Marketing Cloud Connect to its architecture. Under the current setup, each developer has their own developer sandbox. Developers merge their changes into a sandbox for QA regularly, and then once every week, changes are moved to staging, then from staging to production instances.

Which setup should a Solution Architect propose to support this development approach considering costs and data segregation?
A . Set up one Marketing Cloud instance for production, and create a Marketing Cloud sandbox to connect to each of the Service Cloud sandboxes.
B . Set up one Marketing Cloud instance with a business unit for production and one business unit for testing which is connected to all Service Cloud sandboxes.
C . Set up one Marketing Cloud instance for each sandbox in Service Cloud in order to guarantee data segregation.
D . Set up one Marketing Cloud instance to use with sandboxes for testing and replicate all changes to production.

Answer: A

Explanation:

A Marketing Cloud sandbox is a separate instance that can be used for testing and development purposes. It can be connected to multiple Service Cloud sandboxes using Marketing Cloud Connect. This setup allows data segregation and cost efficiency, as opposed to creating multiple Marketing Cloud instances or business units.

References:

https://help.salesforce.com/s/articleView?id=sf.mc_co_marketing_cloud_sandbox.htm&type=5

https://help.salesforce.com/s/articleView?id=sf.mc_co_connect_multiple_salesforce_orgs.htm&type=5