Final answer:
The President has the power to veto bills. Legislation can still become law if both the House of Representatives and Senate override the veto with a two-thirds majority vote. If the President takes no action for 10 days while Congress is in session, the bill automatically becomes law.
Step-by-step explanation:
The correct answer to who has the authority to veto bills is A. the President. When a bill is passed by both the House of Representatives and the Senate, it is sent to the President for approval. If the President does not approve of the legislation, he or she has the power to veto the bill, list objections to it, and send it back to the chamber where it originated. A presidential veto can be overridden if both the House and the Senate pass the bill again with a two-thirds majority vote in each chamber. It's also important to note that if the President does nothing for 10 days while Congress is in session, the bill becomes law without the President's signature (unless Congress adjourns before the 10 days are up, which results in a 'pocket veto').