Answer
Because p is a solution to the system of equations defined below, it is in Col A.
Work Step by Step
$\begin{bmatrix}
-3&-2&0&1\\
0&2&-6&14\\
6&3&3&-9\\
\end{bmatrix}
$~$\begin{bmatrix}
1&0&2&-5\\
0&1&-3&7\\
0&0&0&0\\
\end{bmatrix}
$ Because the system of equations is consistent, p is in Col A.