Which One of the Following Statements Is Accurate When It

Which one of the following statements is accurate when it comes to incumbency reelection rates in Congress?

A) Senate incumbents are more likely than House incumbents to get reelected.
B) Most incumbents lose in their attempt to be reelected because Congress as an institution is very unpopular today.
C) Most incumbents in both chambers routinely get reelected because they insulate themselves from electoral challenges through a variety of tactics.
D) All congressional incumbents are safe from electoral defeat.