A, B and C are three concentric metallic shells. Shell A is the inner most and shell C is the outermost. A is given some charge and shell C is earthed. Select the correct staternent(s),

The distribution of charges is shown in figure. We see that the inner surface of B and C possess the same charge –Q .Also if x is charge on outer surface of C, then 
                                     
$V_c=0$
$\Rightarrow \frac{Q}{4\pi {\in }_{0}c}+\left(\frac{-Q+Q}{4\pi {\in }_{0}c}\right)+\frac{-Q+x}{4\pi {\in }_{0}c}=0$
$\Rightarrow x=0$