A 3-Kg Block Slides Down a Smooth Incline of Length $\circ$

A 3-kg block slides down a smooth incline of length 2 m inclined at 30 ^$\circ$ and hits a level,horizontal rough patch,coming to a stop in 1 m.What is the coefficient of friction between the block and the rough patch?

A) 0.25
B) 0.5
C) 0.33
D) 1.0
E) 0.75