Net force decreasing while pointing right: is speed increasing, constant, or decreasing?

[zachmac5]

An object is moving to the right, and experiencing a net force that is directed to the right. The magnitude of the force is decreasing with time. The speed of the object is:

A) Increasing
B) Constant in time
C) Decreasing

 

[Jebus_Chris]

What does a force cause?
Does the direction of the force ever change?