I will do it in a way that can solve all these kinds of problem.
Of course, you can just substitute every possible answer in and see which one has the highest y value.
BUT I'm going to do this question by completing the square.
First organize the equation by decreasing degrees.
y=-16t^2+32t
Now factor out a -16 to make the x variable have no coefficient.
y=-16(t^2-2t)
Now complete the square.
y=-16(t-1)^2+16
By this if you graph it its the parent graph y=x^2, its a reflection over x axis by the negative sign at the beginning, then a vertical stretch by 16, and then go to the right by 1 then up by 16. This meant that the vertex is (0,0) go right 1 and up 16.
The vertex or the highest point of the graph is point (1,16) This also meant that its after 1 second at 16 feet height. The answer is B.