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 16 minutes for the angle of depression to change from 30° to 60°, how soon after this will the car reach the observation tower?

• A. 8 mins 58 secs
• B. 10 mins 42 secs
• C. 6 mins 0 secs
• D. 8 mins 0 secs