Thanks for posting this question as well as the answer! This was definitely a great one.

Yay! [Does a little dance around the office]

Hi everyone,

As promised i give you the answer now
This was the 16th question of the integration part in Andy Crowe's book.
The right answer was C, and i did choose B i did exactly like Michael did for almost the same reason.

Here is what the book says :

Prioritizing the changes is the job of the project manager. "A" is wrong because you do not want to distract the team at this point - they should be doing the work. "B" is wrong because it is the project manager to help prioritize competing demands. D is incorrect, because changes cannot automatically be denied simply because you are in execution. ( page 81 )

The Book e even says page 49 in the philosophy of integration management.

" You do not want to call a meeting during the execution every time a problem arises. Instead, the project manager should make decisions and keep the team focused on executing the work packages."

You will not have to erase your message finally Cornelius

A- Have the project team meet with the customers to decide which would be easiest and prioritize that one first.
- Here the PM can negotiate the Customers , (means) he should apply ( the appropriate problem resolution techniques ) in order to evaluate and assess both change requests for deciding on what to prioritize .

IMHO...The trick is to find least incorrect answer. So the choices are between B & C. ( D: is wrong. A: "easiest" wrong keyword)
with B...the PM is assigning single person to deal with it. Using authority, picking right person and not disturbing entire team.
He is picking right person to prioritize change control.
With C...Not involving team, the PM may not fully understand scope change and resultant constraints conflicts.
So My answer is B.

(i don't see my reply published, so doing it once again.)

I would go fro C, too. it is not the perfect answer, but it is the best between the options provided.