Q 3. Two concentric shells of uniform density of mass M₁ and M₂ are situated as shown in the figure. The forces experienced by a particle of mass m when placed at positions A, B and C respectively are (given OA = p, OB = q and OC = r)

$$\begin{gathered} \left(A\right) zero, G\frac{M_{1}m}{q^2} and G\frac{\left(M_1+M_2\right)m}{p^2} \\ \left(B\right) G\frac{\left(M_1+M_2\right)m}{p^2}, G\frac{\left(M_1+M_2\right)m}{q^2} and G\frac{M_{1}m}{r^2} \\ \left(C\right) G\frac{M_{1}m}{q^2}, G\frac{\left(M_1+M_2\right)m}{p^2} and zero \\ \left(D\right) G\frac{\left(M_1+M_2\right)m}{p^2}, G\frac{M_{1}m}{q^2}, and zero \end{gathered}$$