1953 AHSME Problem 34

If one side of a triangle is 12 inches and the opposite angle is 30^{\circ}, then the diameter of the circumscribed circle is:

\begin{array}{l} \textbf{(A)}\ 18\text{ inches} \qquad \textbf{(B)}\ 30\text{ inches} \qquad \textbf{(C)}\ 24\text{ inches} \qquad \textbf{(D)}\ 20\text{ inches}\\ \textbf{(E)}\ \text{none of these} \end{array}

Full credit goes to MAA for authoring these problems. These problems were taken on the AOPS website.