A man observes that when he movesup distance C metres on a slope, the angle of depression of a point on the horizontal plane from the base of the slope is $$30^\circ$$, and when he moves up a further distance of C metres, the angle of depression of that point is $$45^\circ$$. The angle of inclination of the slope with the horizontal is ..........

A

$$45^\circ$$

B

$$60^\circ$$

C

$$75^\circ$$

D

$$30^\circ$$