1953 AHSME Problem 43

If the price of an article is increased by percent p, then the decrease in percent of sales must not exceed d in order to yield the same income. The value of d is:

\textbf{(A)}\ \frac{1}{1+p} \qquad \textbf{(B)}\ \frac{1}{1-p} \qquad \textbf{(C)}\ \frac{p}{1+p} \qquad \textbf{(D)}\ \frac{p}{p-1}\qquad \textbf{(E)}\ \frac{1-p}{1+p}

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