7. A parabola has a maximum or minimum point called the
This is the point where the
curve changes direction. If the parabola opens up, the vertex is the
point. If it opens
down, it is the
point.
a) Axis of symmetry, minimum, maximum

b) Vertex, maximum, minimum

c) Axis of symmetry, maximum, minimum

d) Vertex, minimum, maximum

Please just type which letter ASAP, no links.