Electric Flux

The correct option is(A):20 Vm

Option (1) is incorrect because Gauss’s law is valid only for closed surfaces.
Option (2) is correct — Gauss’s law states that the electric flux through a closed surface is proportional to the total electric charge enclosed within the surface.
Option (3) is incorrect — Gauss’s law is used in electrostatics, not for calculating magnetic fields.
Option (4) is incorrect — Gauss’s law is indeed derived based on the inverse square nature of Coulomb’s law.