Thanks for the support, David.
Ahmed, I would like to say one more thing in our defense, which is that most good dictionaries that are published in the United States for use in the United States include strictly BrE definitions for many words. I don't have access to the complete OED, as David does, but I did at least check all of the dictionaries in my house to make sure that that definition of "revise" did not exist. The fact that there is no mention at all of such usage in my books indicates to me that it is relatively uncommon everywhere, so much so that it is virtually unknown in the United States, and that it is not particularly prevalent in the UK either.
I owe it to you to continue to research the subject, though. In the mean time, I like the word "study" to refer to preparing for a test.
As a footnote, I will say that if we accept this definition of "revise", I have to agree with you that both (A) and (B) are equally acceptable answers to your original question.