France requires a majority for the winning

candidate, with a second round run-off election in the event no one has a majority. In a recent election, the candidate who came in second place in the first round got only about one out of six votes in the second-round run-off. Why?
a) No one had a plurality in the first round.
b) Voters who opposed the candidate split their votes among many other candidates in the first round.
c) Voters voted for many different candidates in the second round.
d) The candidate was favored by many people who failed to vote in the first round.

B