Using trigonometric property in the figure,
[tex]\sin \theta=\frac{opposite\text{ side}}{hypotenuse}[/tex][tex]\begin{gathered} \sin \text{ }55^{\circ}=\frac{h}{98\text{ }} \\ h=98\times\sin 55^{\circ} \\ \cong80\text{ ft} \end{gathered}[/tex]Here, h is the height of the hill.
Therefore, the approximate height of the of the roller coaster when it reached the top of the first Hill is 80 ft.
Option A is the answer.