1978 AHSME Problem 2

If four times the reciprocal of the circumference of a circle equals the diameter of the circle, then the area of the circle is

\textbf{(A) }\frac{1}{\pi^2}\qquad \textbf{(B) }\frac{1}{\pi}\qquad \textbf{(C) }1\qquad \textbf{(D) }\pi\qquad \textbf{(E) }\pi^2

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