A Satellite Circles Planet Roton Every 2

Multiple Choice

A satellite circles planet Roton every 2.8 h in an orbit having a radius of 1.2* 107 m. If the radius of Roton is 5.0* 106 m, what is the magnitude of the free-fall acceleration on the surface of Roton?

A) 31 m/s2
B) 27 m/s2
C) 34 m/s2
D) 40 m/s2
E) 19 m/s2