How Do Campaign Contributions Differ from Other Types of Collective-Action

How do campaign contributions differ from other types of collective-action problems?

A) Candidates pay attention to who donates and who does not, so the contribution may still be effective for the donors.
B) Candidates pay attention to who donates and who does not, so the contribution may still be useful for the candidates.
C) Candidates receive contributions from many different groups and individuals, so they are likely to give the most access to their biggest donors.
D) Candidates receive contributions from many different groups and individuals, so they are likely to give the most access to their most consistent donors.
E) Candidates receive contributions from only a few groups and individuals, so donors who give the maximum are still likely to benefit.