A particle of mass m is located at a distance r from the centre of a shell of mass M and radius R. The force between the shell and mass is F(r), if the shell is replaced by a sphere of same mass and radius then the graph of F(r) vs r will be

$F(r)=\left\{\begin{array}{l}\frac{G M m}{r^2}~, ~~r \geq R \\ \frac{4 \pi G \rho r m}{3}, r<R\end{array}\right.$

where ρ is density of sphere.