If You Were to Take the Temperature of Everyone in Class

If you were to take the temperature of everyone in class, assuming no one is sick, you would find that not everyone has a temperature of 98.6°F. Which statement below best explains your findings?

A) If the subject is not at 98.6°F then he or she is in a disease state
B) Most regulated variables, such as temperature, fluctuate continuously and oscillate about the set point due to negative feedback control.
C) An error signal has occurred and a positive feedback response has put the persons in question out of the normal range of function.
D) The measuring instrument is not working properly; everyone has a set point of 98.6°F.
E) Their temperature is no doubt higher than 98.6°F because a positive feedback loop has increased the subjects' metabolism.