A charge Q is distributed over two concentric hollow spheres of radii r and R(R>r) such that their surface densities are equal. The potential at the common center is :
A. √2(R+r)/πε₀Q(R²+r²)
B. 12(R+r)/πε₀Q(R2+r2)
C. 14(R+r)/πε₀Q(R²+r²)
D. 1(R−r)/πε₀Q(R²+r²)