(A) to investigate not only whether research is an independent function at brokerage firms, but also whether conflicts result when analysts own the stocks they write about or when they are
(B) to investigate not only whether research is an independent function at brokerage firms, but also if conflicts result when analysts own the stocks they write about or they are
(C) to not only investigate whether or not research is an independent function at brokerage firms, but also if conflicts result when analysts own the stocks they write about or are
(D) not only to investigate whether or not research is an independent function at brokerage firms, but also whether conflicts result when analysts own the stocks they write about or are
(E) not only to investigate whether research is an independent function at brokerage firms, but also whether conflicts result when analysts own the stocks they write about or when
Solution:
Parallelism + Redundancy
In not only X but also Y X and Y should be parallel.
In B, X and Y are not parallel-- to investigate not only whether but also if
In C and D, or not is redundant in to not only investigate whether or not
E is incorrect because of awkward ending.
A is the best choice. It maintains parallelism.
Sentence Correction - 1000 Questions with Solution: