The correct answer is (A) To back out; to not keep one's promise; to not adhere to one's agreement or position; to abandon; to renounce or revoke.

Renege comes from Latin renegare (re [again] and negare [to deny]).

Examples of use:

• To our surprise, he subsequently reneged on his promise.
• If you join, you cannot afford to renege on any promise or agreement.