Question $3$ Let $A=\left[\begin{array}{ccc}1& 2& 1\\ 1& 3& 2\\ 1& 4& 3\end{array}\right].$ If $u=\left[\begin{array}{c}-4\\ 4\\ -4\end{array}\right]$ which of the following statements is true? $u$ is in the column space of A and $u$ is in the null space of $A.u$ is in the null space of A and $u$ is not in the column space of $A.u$ is not in the column space of A and $u$ is not in the null space of $A.u$ is in the column space of