In a circle with centre O, AB is a diameter and CD is a chord which is equal to the radius OC. AC and BD are extended in such a way that they intersect each other at a point P, exterior to the circle. The measure of ∠APB is

Answer: Option C

∵ OC = CD = radius
According to property of circle

Same arc angle
Make line AD

Angle BDA = 90° because of semicircle property
∠P = 90° - 30° = 60°