The spherical shell of inner diameter R and outer diameter 3R consist of a uniform density e. Determine the magnitude of the gravitational acceleration a distance 2R from the center of the spherical shell?
A) 7>G>R/3
B) 25>G>R/12
C) 32>G>R/5
D) 15>G>R/7
E) 7>G>R/6