What Happens If No Presidential Candidate Receives a Majority of the Electoral

What happens if no presidential candidate receives a majority of the Electoral College votes?

A) Nothing; the candidate with the most votes wins.
B) The House of Representatives decides who wins, with each state getting one vote, and voting continues until someone gets a majority of the votes.
C) The current sitting vice president, in his role as the president of the Senate, chooses the next president.
D) Both the House and the Senate decide who wins with a simple majority vote.