In the figure given below $DE \parallel QR$ and $AP$ and $BP$ are bisectors of $\angle EAB$ and $\angle RBA$ . Then $\angle APB$ is equal to

Question

$\begin{array}{1 1} (a)\;45^{\circ} \\ (b)\;90^{\circ} \\ (c)\;300^{\circ} \\(d)\;120^{\circ} \end{array}$