Physics - Electrostatics Question with Solution | TestHub

Gauss law depends on enclosed net charge, not on whether both charge signs exist.

$\oint \vec{E}\cdot d\vec{S}=0$ when all charge is outside.

$\oint \vec{E}\cdot d\vec{S}=\frac{q}{{ϵ}_0}$ when charge q is enclosed.

Hence B and D.