Participating in a triathlon causes the blood glucose level to decrease. When this happens, the liver releases glucose into the blood. Which feedback mechanism is used to regulate blood glucose? A. a negative feedback loop because the blood glucose level is returned to the set point, not amplified

B. a positive feedback loop because the blood glucose level is returned to the set point, not amplified

C. a positive feedback loop because the Wood glucose level is amplified, not returned to the set point

D. a negative feedback loop because the blood glucose level is amplified, not returned to the set point