1. The correct answer for the problem shown above is the equation of the last option (Option D), which is shown below:
D. y=-3(x+3)^2+6
3. To verify that this is the equation of the parabola, you can give values to the variable "x" and plot each point obtained. When you do this, you obtain the graph attached.
2. Therefore, as you can see in the graph attached the vertices area (-3,6), so you can conclude that the correct answer is the option mentioned before: