Answers resolve YES as soon as that person indicates that they're "running" for the role. They don't need to use that exact language, but they do need to explicitly indicate that they'd like people to vote for them.

Once a new Majority Leader has been selected, all other answers resolve NO.

Given that there may be some ambiguity, I won't bet.

Any answer that is not an original, single person is invalid and will resolve N/A.