Question

In a(n) ________, _______ primary, only declared members of the party can vote on that party's candidate.

Answer 1

It needs to be a closed primary: only in a closed primary the only people to vote are the party members.

A nonpartisan primary is a primary where the candidates do not need to be from that party.- this is not what the question is asking for.
So the correct answer is C) closed/direct.