parametric equations problem

The center field fence in a ballpark is 10 feet high and 400 feet from home plate. A baseball is hit at a point 3 feet above the ground. It leaves the bat at an angle of (theta) degrees with a horizantal at a speed of 100 miles per hour.

x = (v0 cos(theta))t and y = h + (v0 sin(theta))t - 16t^2

The initial velocity is v0 feet per second and the path of the projectile is modeled by the parametric equations. The projectile is launched at a height of "h" feet above the ground at an angle of (theta) with the horizantal.

a) write a set of parametric equations for the path of the baseball.

b) Use a graphing utility to graph the path of the baseball for theta = 15 degrees. Is the hit a home run?

c) Use a graphing utility to graph the path of the baseball for theta = 23 degrees. Is the hit a home run?

d) Find the minimum angle required for the hit to be a home run.

i got everything except for part d) please help me with part d). how do you find the minimum value of theta that you can hit a homerun with in this parametric equation?