Answer: Second option; fy-axis (x, y) = (-x,y)
Explanation:
If we have the point (x,y) and we do a reflection, for example, over the x-axis, means that the point transforms into (x, - y).
If we have the point (x,y) and we do a reflection, for example, over the y-axis, means that the point transforms into (-x, y).
Then the correct option is:
fy-axis (x, y) = (-x,y)
This means that a reflection over the y-axis changes the sign of the other variable.