What is the relationship between resistivity r and conductivity s?

The correct answer is: D. R = 1/s

Resistivity is the measure of how difficult it is for an electric current to flow through a material. Conductivity is the measure of how easily an electric current can flow through a material. The relationship between resistivity and conductivity is given by the equation:

$R = \frac{1}{s}$

where $R$ is the resistivity, $s$ is the conductivity, and $\Omega$ is the ohm.

Option A is incorrect because resistivity and conductivity are inversely proportional to each other. Option B is incorrect because resistivity is not equal to conductivity. Option C is incorrect because resistivity is not greater than conductivity.