Gabrielle is a pilot for McDonald Airlines. Her airplane is cruising at an altitude of 30,000 feet when she begins to descend at a constant rate of 2,500 feet per minute. After 12 minutes, she lands the airplane. The function A(m) represents the airplane's altitude, in feet, m minutes after beginning its descent. What is the range of A(m)
O all real numbers from 0 to 30,000
O all multiples of 12 less than or equal to 30,000
O all multiples of 2,500 less than or equal to 30,000
O all whole numbers from 0 to 30,000