If $\Delta=\begin{vmatrix} 1+x_1y_1&1+x_1y_2&1+x_1y_3\\1+x_2y_1&1+x_2y_2&1+x_2y_3\\1+x_3y_1&1+x_3y_2&1+x_3y_3\end{vmatrix}$ then $\Delta$ is

Question

$\begin{array}{1 1}(A)\;x_1x_2x_3+y_1y_2y_3\\(B)\;x_1x_2x_3y_1y_2y_3\\(C)\;x_2x_3y_2y_3+x_3x_1y_3y_1+x_1x_2y_1y_2\\(D)\;\text{None of these}\end{array}$