A rigid body of mass m is suspended from point O using an inextensible string of length L. When it is displaced through an angle $$\theta$$, what is the change in potential energy of the mass?

A

$$mgL(1-\cos\theta)$$

B

$$mgL(\cos\theta-1)$$

C

$$mgL\cos\theta$$

D

$$mgL(1-\sin\theta)$$