A 25-Kg Child Starts from Rest and Attains a Speed $\circ$

A 25-kg child starts from rest and attains a speed of 4 m/s at the bottom of a 27 ^$\circ$ slide of length 6 m.The coefficient of the kinetic friction of the slide is

A) 0.08.
B) 0.19.
C) 0.22.
D) 0.36.