What is the result of (1234)+(0000)\begin{pmatrix} 1 & 2 \\ 3 & 4 \end{pmatrix} + \begin{pmatrix} 0 & 0 \\ 0 & 0 \end{pmatrix}(1324)+(0000)?
(0000)\begin{pmatrix} 0 & 0 \\ 0 & 0 \end{pmatrix}(0000)
(1234)\begin{pmatrix} 1 & 2 \\ 3 & 4 \end{pmatrix}(1324)
Undefined
(2345)\begin{pmatrix} 2 & 3 \\ 4 & 5 \end{pmatrix}(2435)