If $A$ is a scalar matrix with scalar $k \neq 0$ of order $3$ than $A^{-1}$ is

Question

$$\begin{array} {1 1}(1)\frac{1}{k^{2}}I&(2)\frac{1}{k^{3}}I\\(3)\frac{1}{k}I&(4)kI\end{array}$$