The correct answer is:
A) In early U.S. history, Republican primaries were run by senators. A senator was sent to represent a group of people in an electoral process. By 1915, 30 states had implemented direct primaries in their electoral process. Today, Democrat citizens determine candidates in presidential primaries.
This option effectively summarizes the evolution of the primary election process, mentioning the initial role of senators in representing groups in early elections, the introduction of direct primaries, and the current system where citizens are involved in determining candidates.
Please note that while the answer mentions "Democrat citizens," both major parties now engage citizens in the primary process today, including Republicans, referencing how both parties have evolved in choosing nominees through various primary systems.