AMC 8 1988 Problem 14

$\diamondsuit$ and $\Delta$ are whole numbers and $\diamondsuit \times \Delta =36$. The largest possible value of $\diamondsuit + \Delta$ is $\text{(A)}\ 12 \text{(B)}\ 13 \text{(C)}\ 15 \text{(D)}\ 20\ \text{(E)}\ 37$