1961 AHSME Problem 36

In \triangle ABC the median from A is given perpendicular to the median from B. If BC=7 and AC=6, find the length of AB.

\textbf{(A)}\ 4\qquad \textbf{(B)}\ \sqrt{17} \qquad \textbf{(C)}\ 4.25\qquad \textbf{(D)}\ 2\sqrt{5} \qquad \textbf{(E)}\ 4.5

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