Perform the operation R2←R2−3R1R_2 \leftarrow R_2 - 3R_1R2←R2−3R1 on the matrix (1234)\begin{pmatrix} 1 & 2 \\ 3 & 4 \end{pmatrix}(1324). What is the resulting second row?
[0,−2][0, -2][0,−2]
[0,2][0, 2][0,2]
[3,4][3, 4][3,4]
[0,−1][0, -1][0,−1]