Why are the wrong noprions wrong?

[gmat_perfect]

In the textbook publishing business, the second quarter is historically weak, because revenues are low and marketing expenses are high as companies prepare for the coming school year.

(A) low and marketing expenses are high as companies prepare
(B) low and their marketing expenses are high as they prepare
(C) low with higher marketing expenses in preparation
(D) low, while marketing expenses are higher to prepare
(E) low, while their marketing expenses are higher in preparation

OA: A

[786]

(A) low and marketing expenses are high as companies prepare
(B) low and their marketing expenses are high as they prepare
(C) low with higher marketing expenses in preparation .... awkward construction .
(D) low, while marketing expenses are higher to prepare .... than is missing
(E) low, while their marketing expenses are higher in preparation

A it is !