The heights of two towers are 180 m and 60 m respectively. If the angle of elevation of the top of the first tower from the second is $$60^\circ$$, what is the angle of elevation of the top of the second from the foot of the first?

A

$$30^\circ$$

B

$$60^\circ$$

C

$$45^\circ$$

D

$$22 \frac{1}{2}^\circ$$,