AMC 12 2002a Problem 7

A $45^\circ$ arc of circle A is equal in length to a $30^\circ$ arc of circle B. What is the ratio of circle A's area and circle B's area?

$\text{(A)}\ 4/9 \text{(B)}\ 2/3 \text{(C)}\ 5/6 \text{(D)}\ 3/2 \text{(E)}\ 9/4$