2005 Pascal Problem 4

Six balls, numbered 2, 3, 4, 5, 6, 7, are placed in a hat. Each ball is equally likely to be chosen. If one ball is chosen, what is the probability that the number on the selected ball is a prime number?

\textbf{(A)}\ \frac{1}{6}\quad \textbf{(B)}\ \frac{1}{3}\quad \textbf{(C)}\ \frac{1}{2}\quad \textbf{(D)}\ \frac{2}{3}\quad \textbf{(E)}\ \frac{5}{6}

If there are no answer choices shown, enter a numerical answer.

Full credit to this problem is given to the CEMC, you may view all Pascal contests here.