A man on the top of a vertical observation tower observes a car moving at a uniform speed coming directly towards it. If it takes 12 minutes for the angle of depression to change from 30° to 45°, how soon after this will the car reach the observation tower (approximately) ?
(A) 14 mins 35 secs
(B) 15 mins 49 secs
(C) 16 mins 26 secs
(D) 18 mins 5 secs