The vertex of a parabola that opens downward is at (0, 4). the vertex of a second parabola is at (0, –4). if the parabolas intersect at two points, which statement must be true?

a. the second parabola opens downward.
b. the second parabola opens upward.
c. the points of intersection are on the x-axis.
d. the points of intersection are of equal distance from the y-axis.