AHSME 1995 Problem 18

Two rays with common endpoint $O$ forms a $30^\circ$ angle. Point $A$ lies on one ray, point $B$ on the other ray, and $AB = 1$. The maximum possible length of $OB$ is $\mathrm{(A) \ 1 } \mathrm{(B) \ \frac {1 + \sqrt {3}}{\sqrt 2} } \mathrm{(C) \ \sqrt{3} } \mathrm{(D) \ 2 } \mathrm{(E) \ \frac{4}{\sqrt{3}} }$