From the top of a tower 20m high, a ball is thrown horizontally. If the line joining the point of projection to the point where it hits the ground makes an angle of `45^(@)` with the horizontal, then the initial velocity of the ball is:

Options

A. `10ms^(-1)`
B. `4ms^(-1)`
C. `15ms^(-1)`
D. `3ms^(-1)`

Answer

A