Final answer:
The correct statement regarding the enactment of a tax bill into law is that it must be signed by the President or a presidential veto must be overridden by a two-thirds majority in Congress. The President has ten days to act on a bill after it is presented to them, after which it can become law without their signature unless a 'pocket veto' occurs.
Step-by-step explanation:
The correct statement regarding the enactment into law of a tax bill is, c. A tax law must either be signed into law by the President or Congress must override a presidential veto of the proposed law. According to the legislative process, after both the House of Representatives and the Senate pass a bill, it is presented to the President. The President then has the option to either sign the bill, making it a law, or veto it. If the President vetoes the bill, Congress can override this veto with a two-thirds majority in both houses. Moreover, if the President takes no action on a bill within ten days (excluding Sundays), it automatically becomes law unless Congress adjourns during that period, preventing the return of the bill, which results in what is known as a 'pocket veto.'