2011 AMC8 Problem 21

#1
Students guess that Norb's age is \(24, 28, 30, 32, 36, 38, 41, 44, 47\), and \(49\). Norb says, "At least half of you guessed too low, two of you are off by one, and my age is a prime number." How old is Norb?

\( \textbf{(A) }29\qquad\textbf{(B) }31\qquad\textbf{(C) }37\qquad\textbf{(D) }43\qquad\textbf{(E) }48 \)