Whitney starts the engine on her small private airplane. The engine drives a propeller with a radius of 6.5 feet and its centerline 10.5 feet above the ground. At idle, the propeller rotates at a constant speed of approximately 850 revolutions per minute. The height of one propeller tip as a function of time is given by h = 10.5 + 6.5 sin (850t), where h is the height in feet and t is the time in minutes. Find h when t = 2 minutes

a. 4.1 ft

b. 9.4 ft

c. 16.9 ft

d. 11.6 ft