Use the Figure to Answer the Next Question

Multiple Choice

Use the figure to answer the next question. A light rope runs through two frictionless pulleys of negligible mass. A mass, m, is hung from one of the pulleys and a force, F is applied to one end of the rope so that the mass moves at a constant speed.
-What is the force needed to move the mass at a constant speed?

A) 0
B) mg
C) mg
D) 2mg
E) 4mg