If A=(12)A = \begin{pmatrix} 1 & 2 \end{pmatrix}A=(12) and B=(34)B = \begin{pmatrix} 3 \\ 4 \end{pmatrix}B=(34), what is ABABAB?
(38)\begin{pmatrix} 3 & 8 \end{pmatrix}(38)
111111
Undefined
(11)\begin{pmatrix} 11 \end{pmatrix}(11)