From 9 names on a ballot, a committee of 4 will be elected to attend a political national convention

From 9 names on a ballot, a committee of 4 will be elected to attend a political national convention. How many different committees are possible?

A. 3024
B. 15,120
C. 1512
D. 126

We want unique combinations, so we have 9 choose 4, or 9C4.

Typing this into the search engine, we get:
9C4 = 126 different committees or Answer D