jmc

Acute-angled $△ABC$ is inscribed in a circle with center at $O$; $\stackrel{⌢}{\mathrm{AB}}=120^{\circ }$ and $\stackrel{⌢}{\mathrm{BC}}=72^{\circ }$. A point $E$ is taken in minor arc $AC$ such that $OE$ is perpendicular to $AC$. Then the ratio of the magnitudes of $\angle OBE$ and $\angle BAC$ is: $\text{(A)}\frac{5}{18}\text{(B)}\frac{2}{9}\text{(C)}\frac{1}{4}\text{(D)}\frac{1}{3}\text{(E)}\frac{4}{9}$