Inside a conducting spherical shell of inner radius 3R and outer radius 5R , a point charge Q is placed at a distance R from the centre of the shell. The electric potential at the centre of the shell will be.

A. 1 Q/4πϵ₀R
B. 1 5Q/4πϵ₀6R
C. 1 13Q/4πϵ₀15R
D. 1 7Q/4πϵ₀9R