Answer:
A, D, E
Explanation:
a. "A dog panting to stay cool on a hot day" is a mechanism the dog employs to maintain it's body temperature. This is homeostasis.
d. "A bear hibernates in order to reduce their metabolism and conserve energy during the winter" is also all about keeping the internal condition of the bear's body constant. So this is also an example of homeostasis.
e. The lizard trying to keep regulate it's body temperature is also part of homeostasis.
