An athlete whirls a discus in a circle of radius 80.0 cm. At a certain instant, the athlete is rotating at 10.0 rad/s and the angular speed is increasing at 50 rad/s2. At this instant, find the magnitude of the acceleration.

a. 80 m/s2

b. 40 m/s2

c. 89.4 m/s2

d.78.6 m/s2