In a circle with centre O, PA and PB are tangents to the circle at point A and point B, respectively. C is a point on the major are AB. If $$\angle ACB = 50^{\circ}$$, then find the measure of $$\angle$$ APB.

A

$$80^{\circ}$$

B

$$90^{\circ}$$

C

$$50^{\circ}$$

D

$$100^{\circ}$$