Airplane A takes off and ascends at a rate of 3000 ft/min. At the same time, Airplane B, which is flying at 30,000 ft, begins to descend at a rate of 2500 ft/min. Let h represent the height off the ground in feet, and let t represent time in minutes. Which system models this situation?
A. h = 3000. h = 2500 + 30,000t
B. h = 30,000 + 3000t. h = 30,000 - 3000t
C. h = 2500t. h = 30,000 - 3000t
D.h = 3000t. h = 30,000 - 2500t
