I am sorry I can help more but
Google can graph lines if that helps
You just look up graph of a line with your numbers
H(t) = -16t^2 +42t = -16t(t -2.625)
The maximum height will be reached at t=1.3125. It will be
h(1.3125) = 16*1.3125^2 ≈ 27.6 Which corresponding to the 4th selection
The answer to thus question is 121
