Reasons That Incumbent Senators Have Greater Competition Than Incumbent Members

Reasons that incumbent senators have greater competition than incumbent members of the House include all of the following EXCEPT

A) an entire state is more diverse than a congressional district,providing more of a base for opposition.
B) senators have less personal contact with their constituencies.
C) voters are less likely to know the issue positions of their senators than their representatives.
D) senators tend to draw more visible challengers.
E) Senate challengers are better funded than House challengers.