Which of the following is a basis for the column space of A=(1224)A = \begin{pmatrix} 1 & 2 \\ 2 & 4 \end{pmatrix}A=(1224)?
{(1,2)}\{(1, 2)\}{(1,2)}
{(1,2),(2,4)}\{(1, 2), (2, 4)\}{(1,2),(2,4)}
{(1,0),(0,1)}\{(1, 0), (0, 1)\}{(1,0),(0,1)}
{(2,1)}\{(2, 1)\}{(2,1)}