AHSME 1962 Problem 1

The expression $\frac{1^{4y-1}}{5^{-1}+3^{-1}}$ is equal to: $\textbf{(A)}\ \frac{4y-1}{8} \textbf{(B)}\ 8 \textbf{(C)}\ \frac{15}{2} \textbf{(D)}\ \frac{15}{8} \textbf{(E)}\ \frac{1}{8}$