I think the answer is the first one and the last one .
Hey there!
Use this formula:

Remember this formula.
Now, let's solve the given problem.

Hope this helps you!
~Just a joyful teen

Hope this helps and have a fantabulous day! :)
The the parabola opens upward it has a minimum and if it opens downward then it has a maximum :)
-21.8+18.3
or 18.3-21.8
or the answer which is -3.5