arora007 wrote:source: McGraw Hill's Conquering GMAT Verbal and writing

In recent years a controversy has developed around the
lucrative textbook publishing market as students question if
textbooks should be as expensive as they are and professors
wonder over their accuracy.

A. as students question if textbooks should be as expensive as they
are and professors wonder over their accuracy - No need of if. Use if only in conditional sentence else use whether. 'Their' is very confusing here.
B. as students question the expense and professors wonder about
the accuracy of textbooks - Correct
C. where students question whether textbooks should be as expen-
sive as they are and professors wonder whether they are
accurate - Meaning says that students only question in market and nowhere else. 'They' is confusing here.
D. where students are questioning if textbooks should be as
expensive as they are while professors wonder if they are
accurate - Same as C
E. as students are questioning whether textbooks must be as
expensive as they are and professors wonder about their
accuracy - Use of simple present tense is better than using present continuous tense. Again 'their' is confusing here

If you choose a choice please explain why.

paes wrote:not a good question at all.

See what B is trying to say : 'students question the expense'

expense of what ?? not clear from B.

I would rather prefer E, accepting the pronoun ambiguity.