The correct answer is A. Farad/sq-m.
Permittivity is a measure of how much electric field is required to create a given electric displacement in a material. It is a dimensionless quantity, but it is often expressed in units of farads per square meter (F/m).
A farad is the unit of capacitance, which is the ability of a material to store an electric charge. The permittivity of free space, $\epsilon_0$, is a fundamental constant of nature that has the value $8.854\times10^{-12}$ F/m.
The permittivity of a material, $\epsilon$, is related to the permittivity of free space by the equation $\epsilon=\epsilon_0\epsilon_r$, where $\epsilon_r$ is the relative permittivity of the material. The relative permittivity is a dimensionless quantity that is greater than or equal to 1. It is a measure of how much more easily an electric field can be created in a material than in free space.
The permittivity of a material is important in many areas of physics and engineering, including electromagnetism, optics, and electronics.