A uniform beam of mass m is rests symmetrically on two supports A and B. The forces acting on the beam are shown.
If support B is slid towards the left, how does the force provided by support A change?
[Figure: Uniform beam with supports A and B, forces F at each support, weight mg in center]
A. It is always equal to the force provided by B
B. It remains as F
C. It becomes greater than F
D. It becomes less than F