JEE Main 2020 Physics question

In finding the electric field using Gauss law the formula is applicable. In the formula is permittivity of free space, A is the area of Gaussian surface and is charge enclosed by the Gaussian surface. This equation can be used in which of the following situation ?

• (A)For any choice of Gaussian surface.
• (B)Only when the Gaussian surface is an equipotential surface.
• (C)Only when = constant on the surface.
• (D)Only when the Gaussian surface is an equipotential surface and is constant on the surface.Correct