Which of the following is a natural biorhythm?

Choose the best answer from the options below:
A The human heart (at rest) beats about once per second
B The human lungs (at rest) inhale about once every other second
C The human eyelid normally blinks about once per minute
D The human heart (at rest) beats about once per minute.
E The human eyelid normally blinks about ten times per second

C The human eyelid normally blinks about once per minute

The natural biorhythm out of the given options is:

C) The human eyelid normally blinks about once per minute.