A 5-Cm Radius Conducting Sphere Has a Charge Density of 2

A 5-cm radius conducting sphere has a charge density of 2 * 10^-6 C/m² on its surface. Its electric potential, relative to the potential far away, is:

A) 1.1 * 10⁴ V
B) 2.2 *10⁴ V
C) 2.3 * 10⁵ V
D) 3.6 * 10⁵ V
E) 7.2 * 10⁶ V