Lavanya throws a ball upwards, from a rooftop, which is 20 m above from ground. It will reach a maximum height and then fall back to the ground. The height of the ball from the ground at time t is h, which is given by                                  h =− 4t^2 + 16t + 20 .

On the basis of the given information, answer the following -->
What is the maximum height reached by the ball?
      (a) 54 m (b) 44 m (c) 36 m (d) 18 m