A person on the top of a vertical tower observes a car moving at a uniform speed coming directly towards it. If it takes 6 minutes for the angle of depression to change from 30° to 45°, and further t minutes to reach the tower, which one of the following is correct ?
1
7.7 < t < 8
2
8 < t < 8.3
3
8.3 < t < 8.6
4
8.6 < t < 8.9