Solve this following
Question:

Let $A$ be a matrix such that $A .\left[\begin{array}{ll}1 & 2 \\ 0 & 3\end{array}\right]$ is a scalar matrix and $|3 \mathrm{~A}|=108$. Then $\mathrm{A}^{2}$ equals :

1. $\left[\begin{array}{cc}36 & -32 \\ 0 & 4\end{array}\right]$

2. $\left[\begin{array}{cc}4 & 0 \\ -32 & 36\end{array}\right]$

3. $\left[\begin{array}{cc}4 & -32 \\ 0 & 36\end{array}\right]$

4. $\left[\begin{array}{cc}36 & 0 \\ -32 & 4\end{array}\right]$

Correct Option: 1

Solution: