A conducting sphere of radius 10 cm has unknown charge. If the electric field at a distance 20 cm from the centre of the sphere is `-1.2xx10^(3)NC^(-1)` and points radially inwards. The net charge on the sphere is

Options

A. `-4.5 xx 10^(-9)C`
B. `4.5 xx 10^(9)C`
C. `-5.3 xx 10^(-9)C`
D. `5.3 xx 10^(9)C`

Answer

C