#### Answer

(b) they are the inverse of one another.

#### Work Step by Step

S.I unit of Coulomb force constant k= S.I unit of $\frac{1}{4\pi\varepsilon_{0}}=$
S.I unit of $\frac{1}{\varepsilon_{0}}$ (as there is no unit for $\frac{1}{4\pi}$).
Obviously, S.I unit of $\frac{1}{\varepsilon_{0}}$ is the inverse of the S.I unit of $\varepsilon_{0}$.