Critical Thinking question

I don't know much about physiology/sociology, but isn't it obvious that B is correct?

A is wrong because the person who said these didn't really mean that you are dumb. He just wanted to emphasize the fact that you like bad movies. In addition, he spends a mere sentence for that (so it surely isn't the main issue)

C is wrong too: He mainly wants to tell you that these bad movies doesn't deserve such a high price. In addition, these two last sentences are too few to be considered the main issue.

B is probably correct: The text starts saying that you can't possibly like these moves (which means you have a bad taste in movies). He spends three more sentences trying to convince you that the movies you like are bad. So, most of the text is referred to your bad taste in movies.
The above mean that the main issue is probably B.