Although i cant see the cartoon, you can easily eliminate b and c, the most likely answer is a.
Answer:
Members of The House Of Representatives serve two-year terms and are considered for reelection every even year. Senators however, serve six-year terms and elections to the Senate are staggered over even years so that only about 1/3 of the Senate is up for reelection during any election.
Explanation:
https://studyandanswers.com/social-studies/question512925171
Explanation: