Question

Which is an example of the body maintaining homeostasis using a positive feedback loop?

Answer 1

It would be a negative feedback loop.

and D would be the answer. 

Glucagon stimulates glucose to be released into the blood stream, which would happen if blood glucose was low, and insulin stimulates blood glucose to be taken into cells, which happens when blood glucose is too high. The only one that correctly pairs low blood conc./glucagon and high blood conc./insulin is D.