Which of these matrices has a non-zero determinant?
(1111)\begin{pmatrix} 1 & 1 \\ 1 & 1 \end{pmatrix}(1111)
(0000)\begin{pmatrix} 0 & 0 \\ 0 & 0 \end{pmatrix}(0000)
(1000)\begin{pmatrix} 1 & 0 \\ 0 & 0 \end{pmatrix}(1000)
(1001)\begin{pmatrix} 1 & 0 \\ 0 & 1 \end{pmatrix}(1001)