A Spherical Shell of Radius 9

A spherical shell of radius 9.0 cm carries a uniform surface charge density σ = 9.0 nC/m². The electric field at r = 4.0 cm is approximately

A) 0.13 kN/C.
B) 1.0 kN/C.
C) 0.32 kN/C.
D) 0.75 kN/C.
E) zero.