To reflect the function \( f(x) = (x + 1)^2 \) over the x-axis, we take the negative of the entire function. Therefore, the equation for \( g(x) \) would be:
\[ g(x) = -f(x) = -(x + 1)^2 \]
So the correct answer is:
\[ g(x) = -(x + 1)^2 \]
This matches with the response format:
g(x)=−(x+1)².