A50=A48+A2−I=A46+2( A2−I)=A44+3( A2−I)=A2+24( A2−I)=25 A2−24I
$\begin{aligned}
& =25\left[\begin{array}{lll}
1 & 0 & 0 \
1 & 1 & 0 \
1 & 0 & 1
\end{array}\right]-24\left[\begin{array}{lll}
1 & 0 & 0 \
0 & 1 & 0 \
0 & 0 & 1
\end{array}\right] \
& =\left[\begin{array}{ccc}
1 & 0 & 0 \
25 & 1 & 0 \
25 & 0 & 1
\end{array}\right]
\end{aligned}$
Sum =53
option (1)