Mark the tick against the correct answer in the following:

Mark the tick against the correct answer in the following:

The solution set of the equation $\left|\begin{array}{ccc}\mathrm{x} & 3 & 7 \\ 2 & \mathrm{x} & 2 \\ 7 & 6 & \mathrm{x}\end{array}\right|=0$ is

A. $\{2,-3.7\}$

B. $\{2,7,-9\}$

C. $[-2,3,-7\}$

D. none of these