A balloon is hovering at a height of 200 m above. A man in a boat on a lake observes it at an elevation of $$45^\circ$$. 100 seconds later, he sees it at an angle of elevation of $$30^\circ$$. What is the speed of the boat ?

A

1.5 m/s

B

2.2 m/s

C

2 m/s

D

1.8 m/s