What Was the Practical Purpose for Publication of the Federalist

What was the practical purpose for publication of The Federalist essays in 1788?

A) to allow an avenue for posting opposing political viewpoints
B) to act as a political party platform for the Federalist party
C) to explain and defend the new Constitution and to urge its ratification
D) to expose the immorality inherent in eighteenth-century society
E) to advocate for James Madison's campaign for president