If the matrix $A=\begin{bmatrix} 0 & a & 3\\2 & b & -1\\c & 1 & 0\end{bmatrix}$ is skew-symmetric, then $a+b+c$ is equal to :

-5

The correct answer is Option (4) → -5

'A' is skew symmetric, $A^T=-A$

$⇒\begin{bmatrix}0&2&c\\a&b&1\\3&-1&0\end{bmatrix}=\begin{bmatrix} 0 & -a & -3\\-2 & -b & 1\\-c & -1 & 0\end{bmatrix}$

$⇒a=-2,b=0,c=-3⇒a+b+c=-5$