1988 corporate profits

[LulaBrazilia]

As measured by the Commerce Department, corporate profits peaked in the fourth quarter of 1988 and have slipped since then, as many companies have been unable to pass on higher costs.

(A) and have slipped since then, as many companies have been unable to pass on higher costs

(B) and have slipped since then, the reason being because many companies have been unable to pass on higher costs

(C) and slipped since then, many companies being unable to pass on higher costs

(D) but, many companies unable to pass on higher costs, they have slipped since then

(E) yet are slipping since then, because many companies were unable to pass on higher costs

[Patrick_GMATFix]

Verb tense is tested (since 1988, profits have slipped/slipped) along with modifiers and concision (as/because/the reason being because).

The answer is A. I go through the question in detail in the full solution below (taken from the GMATFix App).



-Patrick