In the Figure, the Horizontal Lower Arm Has a Mass

Multiple Choice

In the figure, the horizontal lower arm has a mass of 2.8 kg and its center of gravity is 12 cm from the elbow joint pivot. How much force F_M must the vertical extensor muscle in the upper arm exert on the lower arm to hold a 7.5 kg shot put?

A) 100 N
B) 500 N
C) 750 N
D) 1000 N
E) 1500 N