A solid sphere of mass m and radius r is placed inside a hollow thin spherical shell of mass M and radius R as shown in figure. A particle of mass `m^'` is placed on the line joining the two centres at a distance x from the point of contact of the sphere and the shell. Find the magnitude of the resultant gravitational force on this particle due to the sphere and the shell if
`2r lt x lt 2R`

Options

A. `(Gmm^')/(4(x-x)^2)`
B. `(Gmm^')/(x-x)^2`
C. `(Gmm^')/(x-r)^3`
D. `(2Gmm^')/(x-r)^2`

Answer

B