Answer:
C.They raise more money and run in gerrymandered ""safe"" districts
Step-by-step explanation:
Gerrymandering is a practice whereby boundaries of electoral district are set by a ruling party to favour them to win the next election.
Gerrymandering is often easy when the state legislative and executive arm is controlled by a single political party. typically in the United States, districts are set every 10 years.
Additionally, an incumbent is most likely to get more campaign donations as his odd of winning is higher and hence people who desire favour from the government will most likely be willing to support an incumbent.