The term of office for a u. s. senator is years, while that of a member of the u. s. house is years. six; two four; two six; four four; four eight; four

Each senator in the US serves a term of 6 years. Each member of the house of representatives serves 2 years.

1/3 of the senators in the senate are up for election every 2 years. So every 2 years about 33 senators have to face the electorate, but once in, they serve for a total of 6 years, and then their group of 33 goes to the poles again. 

The correct answer is a