Three concentric metal shells A , B and C of respective radii a, b , and c `( a lt b lt c ) ` have surface charge densities `+ rho , rho and + rho ` respectively . The potential of shell B is

Options

A. `( rho )/( epsi _(0)) [ ( b^(2) - c^(2) )/( b) +a]`
B. `( rho ) /( epsi_(0 ) ) [( b^(2) - c^(2) ) /( c ) + a]`
C. `( rho )/( epsi _(0)) [ ( a^(2) - b^(2) )/( a)+c]`
D. `( rho )/( epsi _(0)) [ ( a^(2) - b^(2) )/( b)+c]`