A vendor has 18 balloons for sale: 9 are yellow, 3 are red, and 6 are green. A balloon is selected at random and sold. If the balloon sold is yellow, what is the probability that the next balloon selected at random is also yellow?
A9/18
B8/18
C9/17
D8/17
A9/18
B8/18
C9/17
D8/17