Final answer:
The electric flux through a spherical surface due to a dipole within is zero because the positive and negative charges of the dipole cancel out, resulting in no net charge enclosed by the surface.
Step-by-step explanation:
The question is asking about the electric flux through a spherical surface due to a dipole placed inside. According to Gauss's law, the electric flux (Φ) through any closed surface is equal to the charge enclosed (∑q) divided by the permittivity of free space (ε0). In the case of a dipole, the positive and negative charges cancel each other out, resulting in zero total charge enclosed within the spherical surface. Therefore, the answer to the question is D. zero.