For which value of kkk is the matrix A=(1231k3125)A = \begin{pmatrix} 1 & 2 & 3 \\ 1 & k & 3 \\ 1 & 2 & 5 \end{pmatrix}A=1112k2335 singular?
k=2k = 2k=2
k=3k = 3k=3
k=0k = 0k=0
k=1k = 1k=1