1. The person who wins a party's presidential nomination doesn't necessarily need to receive the most votes.

2. More than a third of all delegates for the Democratic National Convention are up for grabs on this one day.

3. No one can win the nomination based on Super Tuesday alone.

4. The race for the Democratic nomination is still wide open.

Which two statements are MAIN ideas of the article?

A
1 and 3

B
2 and 4

C
2 and 3

D
1 and 4