As More States Opted to Hold Presidential Primaries

As more states opted to hold presidential primaries,

A) national party conventions became even more important in the process of nominating candidates for president and vice­president, because it wasn't always clear who the winning candidates would be until the delegates voted.
B) the drama of national party conventions increased.
C) the drama of national party conventions diminished.
D) the candidates' air games and ground games became less important.
E) it was determined that national party conventions would no longer be held.