What is the result of the commutator [A,AT][A, A^T][A,AT] where A=(1234)A = \begin{pmatrix} 1 & 2 \\ 3 & 4 \end{pmatrix}A=(1324)?
(0000)\begin{pmatrix} 0 & 0 \\ 0 & 0 \end{pmatrix}(0000)
(04−40)\begin{pmatrix} 0 & 4 \\ -4 & 0 \end{pmatrix}(0−440)
(0−440)\begin{pmatrix} 0 & -4 \\ 4 & 0 \end{pmatrix}(04−40)
(2002)\begin{pmatrix} 2 & 0 \\ 0 & 2 \end{pmatrix}(2002)