Sentence Correction

The commission'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
banking division.
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

is A correct?