设 $A=\left(\begin{array}{lll}1 & 2 & 3 \\ 0 & 1 & 2 \\ 0 & 0 & 1\end{array}\right), B=\left(\begin{array}{lll}0 & 1 & 0 \\ 0 & 0 & 1 \\ 0 & 0 & 0\end{array}\right), E=\left(\begin{array}{lll}1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1\end{array}\right)$ ，令
$$
M=(A-E)^{2023}+(A-E)^{2022}+\cdots+(A-E)^3+(A-E)^2+A-E
$$
则矩阵 $M=$
A
$\left(\begin{array}{lll}1 & 2 & 1 \\ 0 & 1 & 2 \\ 0 & 0 & 1\end{array}\right)$
B
$\left(\begin{array}{lll}0 & 2 & 3 \\ 0 & 0 & 2 \\ 0 & 0 & 0\end{array}\right)$
C
$\left(\begin{array}{lll}0 & 2 & 5 \\ 0 & 0 & 2 \\ 0 & 0 & 0\end{array}\right)$
D
$\left(\begin{array}{lll}0 & 2 & 7 \\ 0 & 0 & 2 \\ 0 & 0 & 0\end{array}\right)$ ．
E
F