What Is the Idea Behind a Closed Primary System

What is the idea behind a closed primary system?

A) Any registered voter should have a say in who will lead both of the major parties in the general election.
B) Voters should be allowed to choose freely from a list of every candidate regardless of party affiliation.
C) Voters should not be forced to make public their choice in the primary election for who will lead them in the general election.
D) Only party members should be able to determine who will lead them in the general election.
E) If no candidate receives a majority of the vote in the first election, further elections should be run in order for one candidate to gain a majority.