Which of the following vectors is parallel to a⃗=(12)\vec{a} = \begin{pmatrix} 1 \\ 2 \end{pmatrix}a=(12)?
(24)\begin{pmatrix} 2 \\ 4 \end{pmatrix}(24)
(−1−2)\begin{pmatrix} -1 \\ -2 \end{pmatrix}(−1−2)
(21)\begin{pmatrix} 2 \\ 1 \end{pmatrix}(21)
(01)\begin{pmatrix} 0 \\ 1 \end{pmatrix}(01)