To reflect the function \( f(x) = (x + 1)^2 \) over the x-axis, we need to negate the entire function.
The reflection over the x-axis is done by changing \( f(x) \) to \( -f(x) \):
\[ g(x) = -f(x) = -((x + 1)^2) \]
Thus, the equation for \( g(x) \) is:
\[ g(x) = -(x + 1)^2 \]
Therefore, the correct response is:
g(x) = −(x + 1)².