A horizontal reflection of a point \((x, y)\) in the coordinate system changes the x-coordinate from \(x\) to \(-x\), while leaving the y-coordinate unchanged.
Given the point \((-2, 1)\), reflecting it horizontally would result in:
- The x-coordinate changes from \(-2\) to \(2\).
- The y-coordinate remains \(1\).
So, the reflected point is \((2, 1)\).
Therefore, the correct response is:
In the horizontal reflection, the point \((-2, 1)\) becomes \((2, 1)\).