715. The commissior’s office of compliance, inspections, and investigations plans to intensify its scrutiny of stock analysts 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 paid for their work by a firm’s investment.

(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.

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