A person sitting on the ground floor of a building notices through the window, of height 1.5 m , a ball dropped from the roof of the building crosses the window in 0.1 sec . What is the velocity of the ball when it is at the topmost point of the window ? (`g =10 m//s^2)

Options

A. 15.5 m/s
B. 14.5 m/s
C. 4.5 m/s
D. 20 m/s