Shown in the figure are two point charges $+Q$ and $-Q$ inside the cavity of a spherical shell. The charges are kept near the surface of the cavity on opposite sides of the centre of the shell. If $\sigma_1$ is the surface charge on the inner surface and $Q_1$ net charge on it and $\sigma_2$ the surface charge on the outer surface and $Q_2$ net charge on it then :

Question

$\begin{array}{1 1} \sigma_1 \neq 0,Q_1 \neq 0, ; \sigma_2\neq 0 ,Q_2 \neq 0 \\\sigma_1 \neq 0,Q_1 = 0, ; \sigma_2\neq 0 ,Q_2 =0 \\\sigma_1 \neq 0,Q_1 = 0, ; \sigma_2 = 0 ,Q_2 = 0\\ \sigma_1 = 0,Q_1 = 0 ; \sigma_2 = 0 ,Q_2 = 0\end{array}$