What Benefit Do PACs Offer Economic and Policy Groups

What benefit do PACs offer economic and policy groups?

A) Groups are able to curry the favor of a candidate without public knowledge.
B) Groups are able to keep any money the candidate does not need.
C) Groups avoid internal conflict because members do not know of the connection between the group and the candidate.
D) PACs are a lawful way to influence campaign politics.
E) PACs are a way to bolster their treasuries without having to report it to the IRS.