Answer:
A. His ideas became the basis for many of the document's fundamental provisions.
Explanation:
Madison was a stalwart in defense of the new plan. Joining with Alexander Hamilton and John Jay to write a series of essays that could help turn public opinion toward ratification, Madison was a prime author of what became known as The Federalist—an oft-reprinted series of newspapers and then pamphlet articles. No one has absolutely identified the individual author of each of the 85 essays. Hamilton wrote more than 50 essays and Madison fewer than 20. Yet his acknowledged authorship of "Federalist Number 10," arguing that private rights and public good would be best protected in a single large republic rather than a mélange of small republics, cemented Madison's reputation as a nationalist and a political genius.