To find the reflection of the function \( f(x) = x^2 - x \) over the y-axis, we need to replace \( x \) with \( -x \) in the function.
So, we calculate:
\[ g(x) = f(-x) = (-x)^2 - (-x) = x^2 + x \]
Therefore, the function \( g(x) \) is:
\[ g(x) = x^2 + x \]
The correct response is:
g(x) = x² + x