सही विकल्प है (D) 4
\(\begin{vmatrix}-a&b&c\\a&-b&c\\a&b&-c \end{vmatrix} = kabc\)
\(abc\begin{vmatrix}-1&1&1\\1&-1&1\\1&1&-1 \end{vmatrix} = kabc\) (by taking a, b, c out of the matrix from column \(C_1, C_2, C_3\) respectively)
\(\begin{vmatrix}-1&1&1\\1&-1&1\\1&1&-1 \end{vmatrix} = k\) (dividing by abc on both side)
\(\begin{vmatrix}-1&0&0\\1&0&2\\1&2&0 \end{vmatrix} = k\) (by using \(C_2 \leftarrow C_2 + C_1 \) and \(C_3 \leftarrow C_3 + C_1 \))
\(-1(0\times0 - 2 \times 2) = k\)
\(-1(-4) = k\)
\(\therefore k = 4\)
