TOPIC: Explain the Answer please

Please see the attachment. I took PMI sample test today. This question is not clear to me.
From my perspective, Scope should be approved before the execution of the Project. So, I don't know to interpret this question. Please help.

Option C looks tempting but question is asking about how to avoid the issue in future. Now, in future if the PM does the demo again, then we will see the same issue again. Demo is done after the deliverable. But obviously we have to do something before the deliverable to sort out the issue. Also, selecting option C means taht the functionality is already present and somehow the stakeholders are unable to figure out that functionality.(An assumption which goes against the basic information provided in the question)
If we had an option like "Raise a change request" then probably we all would have marked that one as right answer, and rightly so. But, the option A goes one step further and says that the raised change request has to be approved. This is how I understand. This one was little tricky given that we due the the limited time we may not be able to think that deep.

Ha.. Thanks, Vivek. A clear explanation, I understood now. But seriously, thinking how can we even think to that level of detail in the exam.
That's PMP!