A student makes ice cream using an old-fashioned hand-crank machine. He does 40 joules of work each time he turns the crank in a complete circle. The crank handle makes a circular path with a diameter of 0.5 meters. The student turns the crank at a rate of once every 1.6 seconds.

What is the average power the student’s body produces to operate the machine?

A) 16 watts
B) 25 watts
C) 64 watts
D) 100 watts