Answer
Graph A: $y = -0.5 x^2-x+7$
Graph B: $y = x^2+4 x+4$
Graph C: $-2 x^2-6 x-7$
None: $y=x^2-5 x-6$
Work Step by Step
Graph A can be matched with the parabola $$y=-x^2+20.$$
This is because it opens downward, $a= -1$, and has a $y$-intercept of about $(0,20)$.
Graph B matched with $$y=x^2-7.$$ It opens upward
$y$-intercept: $(0,-7)$.
Graph C matched with $$y=x^2.$$ It opens upward
$y$-intercept: $(0,0)$.
Matched with none: $$y=-x^2.$$ It opens downward
$y$-intercept: $(0,0)$.
