If A=\left[\begin{array}{ccc}1 & 0 & 0 \ 0 & 1 & 0 \ 0 & 0 & 1]\end{array}, then what is 23 {\A}^3-19 {\A}^2-4 {\A} equal to ? [NDA II 2023]

Correct Answer is : Null matrix of order 3

\left[\begin{array}{ccc}2 & 0 & 0 \ 0 & 2 & 0 \ 0 & 0 & 2]\end{array}

\left[\begin{array}{ccc}7 & 0 & 0 \ 0 & 7 & 0 \ 0 & 0 & 7]\end{array}