Why Are Campaign Contributions So Important for Interest Groups Seeking

Why are campaign contributions so important for interest groups seeking to influence government?

A) Legislators only grant meetings with interest groups that offer campaign contributions.
B) Campaign contributions help elect candidates who are friendly to groups' goals.
C) Groups can offer contributions in return for favorable votes on pending legislation.
D) Organizations seeking to offer input on a political party's platform are required to make campaign contributions.
E) There are very few restrictions on campaign contributions, compared to restrictions on lobbying.