The correct answer is: B. Always at 90°
An electric field line is a graphical representation of the electric field around a charged particle. It is a vector quantity, meaning that it has both magnitude and direction. The direction of the electric field line is from positive to negative charge.
An equipotential surface is a surface on which the electric potential is the same. The electric potential is a scalar quantity, meaning that it has only magnitude.
The electric field lines and the equipotential surfaces are always at right angles to each other. This is because the electric field is perpendicular to the equipotential surfaces. The electric field is the force that would be exerted on a positive charge, and the equipotential surfaces are the surfaces on which the force would be zero.
Option A is incorrect because the electric field lines and the equipotential surfaces are not always parallel. In fact, they are always at right angles to each other.
Option C is incorrect because the electric field lines and the equipotential surfaces are not always inclined at any angle. They are always at right angles to each other.
Option D is incorrect because the electric field lines and the equipotential surfaces are always at right angles to each other.