Which of the following statements are true regarding satiety and hunger?
A. Glucagon, released from the pancreas when blood glucose levels are low, stimulates the hypothalamus to perceive hunger
B. Signals from the stomach and small intestine stimulate the hypothalamus to perceive satiety and hunger
C. an increase in blood glucose levels stimulates the pancreas to release insulin and the hypothalamus to perceive satiety
D. all of these are true