2000 Cayley Problem 12

Natural numbers are equally spaced around a circle in order from 1 to n. If the number 5 is directly opposite the number 14, then n is

\textbf{(A)}\ 14\quad \textbf{(B)}\ 15\quad \textbf{(C)}\ 16\quad \textbf{(D)}\ 18\quad \textbf{(E)}\ 20

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 Cayley contests here.