On a windy morning, a hot air balloon starts rising and flying away from the top of a hill. The altitude, h, in feet, of the balloon x hours after starting its ascent from the hill, can be modeled by the function h(x) = –16x2 + 64x + 80. What is the y-intercept for this function and what does it represent in the given situation? A. 80; the beginning height of the hot air balloon

B. 80; how long the hot air balloon was in the air

C. 5; the ending height of the hot air balloon

D. 5; how long the hot air balloon was in the air