Answer:
C
Explanation:
vertex form:
the negative sign in front of x^2 is also -1, which is the "a". A controls if the parabola will opek up or down, and the width of the function. In this problem, the parabola opens down. the -3 corresponds to "k" in vertex form. K is the vertical shift or the y coordinate of the vertex. If k is positive it moves up, and if it is negative it moves down. Because of the -3, the vertex of the parabola will move down 3 units on the y-axis.