(D) Members are elected in statewide elections
Each state has two senators, who serve six-year terms, put into office by direct election in their respective state.
Looking at the wrong answers;
A) BOTH the House of the Senate and the House of Representatives can call for a conference committee
B) Representatives hold two-year terms
C) Gerrymandering is a little complicated, but it deals with re-drawing state boundaries to have better odds or votes in one area versus others.
The only correct answer applying to the Senate would be D.