To determine the domain of the function represented by the parabola described, we need to identify the values of \( x \) for which the function is defined.
A parabola typically extends infinitely in the x-direction unless there's a restriction. The vertex of the parabola is at (0, 4), and it opens downwards because it has x-intercepts at (-2, 0) and (2, 0). This indicates that the parabola does not have any restrictions limiting the x-values.
Thus, the domain of the function is:
D. x is all real numbers.
This means that the parabola can take any x-value and still produce a corresponding y-value.