Describe how the graph of y = −4x2 differs from the graph of y = −x2 . A. The graph of y = −x2 is narrower than the graph of y = −4x2. B. The graph of y = −4x2 is narrower than the graph of y = −x2. C. The graph of y = −4x2 is the same as the graph of y = −x2 but shifted down by 4 units. D. The graph of y = −4x2 opens upward while the graph of y = −x2 opens downward.