Pretty sure it's B, since only Change Management with Cloud Transport Management lets you actually control and enforce extensions in a compliant way. The other options help with monitoring or service info but don't address compliance for clean core. Correct me if I'm off!
I don't think it's C. Scope (A) acts as the actual container for solution processes in SAP Cloud ALM, not just something visual like Solution Value Flow. C is tempting but that wording is a trap I've seen before in practice sets. Pretty sure Scope is right unless SAP changed something recently, anyone disagree?
I remember a similar scenario from labs on a practice test, got tripped up by C too. But I think it's actually A here since Scope is what holds the solution processes together in SAP Cloud ALM. Not totally locked in though, open to debate between A and C.