Answer:
It is already telling you the vertex, it just wants to know what you think this represents.
Step-by-step explanation:
Read the first sentence again, he is throwing a ball. Then the second sentence says the equation is the height of the ball, so you know the vertex has to do with the height of the ball. How do you think that height would compare with the other heights of the ball? Would probably be obvious if you sketched a little picture of the graph:)