请教：GWD 一道题，没见谁在讨论

The commission’s office of
compliance, inspection, and investigations plans to intensify its security of
stock analysts to investigate not only whether research is an independent
function at brokerage firms, but also whether conflicts results 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 results when analysts
own the stocks they write about or when they are paid

B.      
to investigate not only whether research is an independent
function at brokerage firms, but also if conflicts results 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 results 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

答案是a，但results 的数解释不通啊