The iugnsemted matrix for a system of linear equation is $\left(\begin{array}{ccc|c}1 & k & 0 & 4 \\ 0 & 1 & k & -2 \\ 1 & 0 & 2 k & 0\end{array}\right)$. Detemiae the valueis of $k$ for which the syiens has infiaitely many solutions.
a) $0 k \times-2$
b) $5=2$
c) $\quad k=0$
d) $k=-2$
e) $\mathrm{k} \neq-2, k \neq 0$