If P'(x', y') is the reflection of the point P(x, y) on the x-axis, then the matrix which describe the reflection of point P(x, y), in the x-axis is :

Given:
Reflection is in the x -axis
Concept used:
Reflection of  P(x, y) in the  x -axis gives P'(x, -y) 
This corresponds to the matrix transformation:
​$$\begin{bmatrix}1 & 0 \\0 & -1\end{bmatrix}\begin{bmatrix}x \\y\end{bmatrix}=\begin{bmatrix}x \\-y\end{bmatrix}$$​​
Therefore, the required matrix is:
​$${\begin{bmatrix}1 & 0 \\0 & -1\end{bmatrix}}$$​​
Correct answer is (d)