What is the difference between a caucus and a primary?

"What is the difference between a caucus and a primary? "

The first difference between a caucus and a primary is who organizes them. A caucus is organized by the political parties in that state; a primary is run by the state government like any other election. A caucus is a much more complicated procedure and involves people meeting in a variety of locations such as community centers, schools and churches.

Caucus processes differ somewhat by state but generally it involves registered party members gathering to discuss candidates and then select delegates for the party conventions. Supporters of each candidate or party leaders have an opportunity to speak and try to convince attendees to support their candidate. The caucus also gives supporters of more viable candidates an opportunity to woo backers of lower-polling contenders.

the answer is option a.