The key on this one may not actually be in the diagram. The diagram tends to work best when we have an A causes B type of situation, though it will certainly also work in other situations in some cases.
In this problem your best bet is to look at the one and the logic behind it.
We have a situation where we have a situation -- theater closing because low attendance.
Then we have an apparent exception -- last week of high attendance.
The conclusion takes this small sample and applies it to the whole situation, erroneously.
In the right answer (D), we have another setup where we have another small sample being used to represent a much larger group -- the group who attended the meeting representing all students...