K. should be your answer.
If t = 0.
Note that the equation has a t in all variables except for c, which will affect the outcome of h (or the first one, as t can change at all times).
If the time is set to 0, the maximum height will only be the height seen at the place where x = 0, which, instead of the true maximum height.
The t intercept will also change, and would not project as far, seeing that it can only 0, instead of t > 0.
hope this helps