The sentence “They are free to listen to and live by their circadian rhythms.” (Line 2-3,
The sentence “They are free to listen to and live by their circadian rhythms.” (Line 2-3, Para. 4) probably means
A.they can live by their biological clocks without referring to man-made ones.
B.they can listen to rhythms of biological clocks and live close to them.
C.they can live their lives by regulating their own circadian rhythms.
D.they are free from the annoying rhythms of everyday life.