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
B. as students question the expense and professors wonder about
the accuracy of textbooks
C. where students question whether textbooks should be as expen-
sive as they are and professors wonder whether they are
accurate
D. where students are questioning if textbooks should be as
expensive as they are while professors wonder if they are
accurate
E. as students are questioning whether textbooks must be as
expensive as they are and professors wonder about their
accuracy

If you choose a choice please explain why.

OA-B