Which Statement Best Describes How a Presidential Primary Works

Which statement best describes how a presidential primary works?

A) Voters participate in an election to select delegates for a candidate to represent a state at the national convention.
B) An election is held nationwide to select a nominee, with the candidate who achieves a plurality winning the nomination.
C) The party organization at the national level holds a final debate where the attendees decide who will receive the nomination.
D) Delegates for a party meet in secret to review poll results, public opinion, debate outcomes, and fundraising to select a nominee.