If O is center of a circle and AO and OB are radius of the circle, and AP and PB are tangents, then what is the angle $\angle{AOB}$ ?

Question

$\begin{array}{1 1} ( a)\; 150^{\circ} \\ (b)\;110^{\circ} \\ (c)\; 115^{\circ} \\ (d)\; 120^{\circ} \end{array}$