155. Aviation officials have not only failed to determine the cause of the crash, but they have also ignored demands by the pilots union that the investigation should be expedited.

(A) crash, but they have also ignored demands by the pilots union that the investigation should be expedited
(B) crash but also ignored demands by the pilots union that the investigation be expedited
(C) crash but have ignored demands for expediting the investigation by the pilots’ union
(D) crash, but they are also ignoring the pilots’ union’s demands to expedite the investigation
(E) crash: the demands by the pilots’ union that the investigation should be expedited have also been ignored

Solution:

Parallelism*

“Not only…but also” is the correct usage. B is the only choice with this usage.
B is the best choice.

​Sentence Correction - 1000 Questions with Solution: