The unit of dielectric strength is given by

V/m
V2/m
m/V
m/V2

The correct answer is A. V/m.

Dielectric strength is a measure of the ability of an insulator to withstand an electric field without breaking down. It is usually expressed in volts per meter (V/m).

Option B, V2/m, is not a valid unit of measurement.

Option C, m/V, is the unit of resistivity.

Option D, m/V2, is the unit of conductivity.