There are three co-centric conducting spherical shells A , B and C of radii a , b and c respectively ( c > b > a ) and they are charged with charge q1 , q2 and q3 respectively. The potentials of the spheres A, B and C respectively, are: Choose the correct answer: A \frac{1}{4\pi\epsilon_0} \left( \frac{q_1}{a} + \frac{q_2}{b} + \frac{q_3}{c} \right), \frac{1}{4\pi\epsilon_0} \left( \frac{q_1+q_2+q_3}{b} \right), \frac{1}{4\pi\epsilon_0} \left( \frac{q_1+q_2+q_3}{c} \right)
B \frac{1}{4\pi\epsilon_0} \left( \frac{q_1+q_2+q_3}{a} \right), \frac{1}{4\pi\epsilon_0} \left( \frac{q_1+q_2+q_3}{b} \right), \frac{1}{4\pi\epsilon_0} \left( \frac{q_1+q_2+q_3}{c} \right)
C \frac{1}{4\pi\epsilon_0} \left( \frac{q_1+q_2+q_3}{a} \right), \frac{1}{4\pi\epsilon_0} \left( \frac{q_1+q_2}{b} + \frac{q_3}{c} \right), \frac{1}{4\pi\epsilon_0} \left( \frac{q_1}{a} + \frac{q_2}{b} + \frac{q_3}{c} \right)
D \frac{1}{4\pi\epsilon_0} \left( \frac{q_1}{a} + \frac{q_2}{b} + \frac{q_3}{c} \right), \frac{1}{4\pi\epsilon_0} \left( \frac{q_1+q_2}{b} + \frac{q_3}{c} \right), \frac{1}{4\pi\epsilon_0} \left( \frac{q_1+q_2+q_3}{c} \right)