Charge of Uniform Density (40 PC/m²) Is Distributed on a Spherical

Multiple Choice

Charge of uniform density (40 pC/m²) is distributed on a spherical surface (radius = 1.0 cm) , and a second concentric spherical surface (radius = 3.0 cm) carries a uniform charge density of 60 pC/m². What is the magnitude of the electric field at a point 4.0 cm from the center of the two surfaces?

A) 3.8 N/C
B) 4.1 N/C
C) 3.5 N/C
D) 3.2 N/C
E) 0.28 N/C