Which of the following is a symmetric matrix?
(1221)\begin{pmatrix} 1 & 2 \\ 2 & 1 \end{pmatrix}(1221)
(1234)\begin{pmatrix} 1 & 2 \\ 3 & 4 \end{pmatrix}(1324)
(01−10)\begin{pmatrix} 0 & 1 \\ -1 & 0 \end{pmatrix}(0−110)
(1220)\begin{pmatrix} 1 & 2 \\ 2 & 0 \end{pmatrix}(1220)