A Man Pulls a 100-N Crate Up a Frictionless 30°slope

A man pulls a 100-N crate up a frictionless 30°slope 5 m high as shown.Assuming that the crate moves at constant speed, the work done by the man is:

A) -500 J
B) -250 J
C) 0 J
D) 250 J
E) 500 J