31. An airplane taking off from an airport climbs at a constant angle of ascent so that it will reach an altitude of 10,000 feet when the airplane has flown 8 miles, as illustrated in the figure below. Which of the following expressions gives the angle of ascent?

(Note: 1 mile = 5,280 feet)

A. Arcsin

B. Arctan

C. Arcsin

D. Arccos

E. Arctan