Hi Ron -
Admittedly, on first read I was agreeing with you, but I think this is one of those cases where, as Puneet pointed out, you have to be careful of exactly where you are in the process with regards to how the question is worded.
Here's the explanation for that question from the self-assessment you referenced:
Explanation: The answer should be a monitoring and controlling process. If a change request regarding changes in project scope is requested after the approval of the Scope Baseline, the change request must be analyzed during the Control Scope process before forwarding it to the Integrated Change Control process for approval.
Reference: PMBOK Guide 5th Edition, page 136
In this case, the stakeholder is asking for a change, but this isn't a change request in the formal sense. This would be more like you're having a conversation with the stakeholder, and s/he says "you know what would be great is if we could add a dashboard to that interface ... can we get that added in?"
Now take a look at the first sentence on page 137 of the PMBOK guide: "Controlling the project scope ensures all requested changes and recommended corrective or preventative actions are processed through the Perform Integrated Change Control process." In other words, Controlling Scope is presented as the process in which we catch these conversations before any action is taken, package up the formal change request (including expected impacts), and kick it over to the Perform Integrated Change Control process.
So while it looks like the question is asking "where do we analyze change requests" (in which case the answer would have been B, as you selected), the question is really asking "where do we listen to requests for scope change and package them up as formal change requests" (thus, the correct answer is D). And this makes sense if you think about it in a real-world context - while we say that the CCB is "analyzing" a change request to make a decision, the expectation in the real world is that the PM is already going to have answers to basic questions like "how much will this cost" and "what will this do to our schedule" ready for the CCB to consider.
While I'd love to be able to tell you that the wording on the actual exam will be less nuanced, this isn't always the case - I ran into a few questions like this with regards to the Initiation process group, where it wasn't quite clear which phase we were in and I had to go with my best guess. The good news is that there weren't that many of them, so if you get a few of these wrong in your practice exams, just take note of any gotchas noted in the explanations so you know what to watch for next time, then shake it off and move on.