Graph the equation. Identify the vertex and the axis of symmetry.
y=-3x^2-6

Select one:
a. Vertex: (0, 6)
Axis of symmetry: x = 0

b. Vertex: (6,0)
Axis of symmetry: x = 6

c. Vertex: (0, -6)Axis of symmetry: x = 0
d. Vertex: (-6, 0)
Axis of symmetry: x = -6