Answer: b. the output of a system keeps conditions within the body absolutely constant only in a negative feedback loop.
Explanation:
In the negative feedback loop, the feedback reduces the excessive response of the stimulus for example regulation of body temperature, and control of blood glucose level. In the positive feedback loop, the response of a stimulus is intensified. Example, positive feedback is the childbirth and blood clotting. According to the negative feedback loop the output of the system keeps the internal body environment constant with respect to the changes in the external environment hence, maintains the homeostasis.
