What is the adjacency matrix for the following graph?

Question $21$

What is the adjacency matrix for the following graph?

$\left[\begin{array}{ccc}1& 0& 0\\ 1& 1& 1\\ 0& 0& 1\end{array}\right]$

$(-)\left[\begin{array}{ccc}1& 0& 0\\ 0& 1& 0\\ 0& 0& 1\end{array}\right]$

$-\left[\begin{array}{ccc}1& 1& 1\\ 1& 1& 1\\ 1& 1& 1\end{array}\right]$

$\left[\begin{array}{ccc}1& 1& 0\\ 1& 1& 1\\ 0& 1& 1\end{array}\right]$