For the matrix A=(1234)A = \begin{pmatrix} 1 & 2 \\ 3 & 4 \end{pmatrix}A=(1324), what is A−1A^{-1}A−1?
(−211.5−0.5)\begin{pmatrix} -2 & 1 \\ 1.5 & -0.5 \end{pmatrix}(−21.51−0.5)
(−213−1)\begin{pmatrix} -2 & 1 \\ 3 & -1 \end{pmatrix}(−231−1)
(1234)\begin{pmatrix} 1 & 2 \\ 3 & 4 \end{pmatrix}(1324)
(2−1−1.50.5)\begin{pmatrix} 2 & -1 \\ -1.5 & 0.5 \end{pmatrix}(2−1.5−10.5)