AHSME 1962 Problem 2

The expression $\sqrt{\frac{4}{3}} - \sqrt{\frac{3}{4}}$ is equal to: $\textbf{(A)}\ \frac{\sqrt{3}}{6} \textbf{(B)}\ \frac{-\sqrt{3}}{6} \textbf{(C)}\ \frac{\sqrt{-3}}{6} \textbf{(D)}\ \frac{5\sqrt{3}}{6} \textbf{(E)}\ 1$