A Mass M Is Placed on a Rough Incline at an Angle

Multiple Choice

A mass m is placed on a rough incline at an angle $\theta$ to the horizon. A force F is applied up the incline, to prevent the mass from sliding down the incline, and it is just enough to prevent the mass from sliding down the incline. Using the compass rose, the direction of the frictional force is along

A) a.
B) b.
C) c.
D) d.
E) e.