To understand how a horizontal reflection affects the point \((-2, 1)\), we need to clarify what a horizontal reflection entails.
A horizontal reflection across the y-axis changes the x-coordinate of a point to its negative. This means:
\[ (x, y) \rightarrow (-x, y) \]
For the point \((-2, 1)\):
- The x-coordinate \(-2\) becomes \(-(-2) = 2\).
- The y-coordinate remains the same, which is \(1\).
Therefore, the point \((-2, 1)\) after a horizontal reflection becomes:
\[ (2, 1) \]
Thus, the correct response is:
In the horizontal reflection, the point \((-2, 1)\) becomes \((2, 1)\).