Which matrix represents a horizontal shear by factor k=2k=2k=2?
(1201)\begin{pmatrix} 1 & 2 \\ 0 & 1 \end{pmatrix}(1021)
(1021)\begin{pmatrix} 1 & 0 \\ 2 & 1 \end{pmatrix}(1201)
(2001)\begin{pmatrix} 2 & 0 \\ 0 & 1 \end{pmatrix}(2001)
(1002)\begin{pmatrix} 1 & 0 \\ 0 & 2 \end{pmatrix}(1002)