Apply Gauss’s law

The net electric flux through any closed surface is $\Phi = \frac{Q_{\text{enclosed}}}{\varepsilon_0}$

where $Q_{\text{enclosed}}$ is the total charge inside the closed surface.

Analyze the dipole

An electric dipole consists of two charges: $+q \text{ and } -q$ of equal magnitude and opposite sign.

Therefore, the total enclosed charge is $Q_{\text{enclosed}} = (+q) + (-q) = 0$

Find the net flux

Using Gauss’s law, $\Phi = \frac{0}{\varepsilon_0} = 0$

So, the Assertion A is true.

Check the Reason R

The statement "Electric dipole consists of two equal and opposite charges" is correct.

So, Reason R is true.

Check whether R explains A

Since the dipole has equal and opposite charges, the total enclosed charge is zero. By Gauss’s law, this makes the net flux through the closed surface zero.

Hence, R is the correct explanation of A.

Correct option

$\boxed{\text{D}}$

Comparison with stored answer

Stored correct answer: $\text{D}$

Derived answer: $\text{D}$

They match.