Two Concentric Conducting Spheres of Radii a = 5 Cm

Two concentric conducting spheres of radii a = 5 cm and b = 10 cm have a potential difference V = 100 V between them. What is the charge carried by each sphere?

A) 100 nC
B) 5.5 nC
C) 1.1 nC
D) 10 nC
E) 2.2 nC