Tough. Choice (E) is correct.
You can tell by using the
contrapositive on both of these statements:
If not (prices fall as rapidly as/more rapidly than
competitors),
then not (production costs fall as rapidly or more ...
I just upgraded my course, should I be going through all of the question sets after a section in a row? (The way it is presented in the syllabus?) OR is there an alternative that I'm missing. Thanks.