The correct answer is C) Reflection across the Y-axis.
Step-by-step explanation:
This is because only the x-coordinates changed. If these coordinates were reflected across both the x and y axis' the sign of both the x and y coordinates would have changed. When you reflect a point across the x axis, the y-coordinates change their sign. When you <u><em>reflect </em></u><u>a point across the y axis</u>, the <u>x-coordinates change</u> their sign.