A hedgehog lives in a backyard in England. Every night, the house owner puts out a bowl of canned cat food and hard-boiled egg. The hungry hedgehog eats some of the food, then stops when it is no longer hungry. This pattern helps the hedgehog to maintain a steady energy level and weight. What is the name for keeping a stable internal environment despite changes in the outside environment?

A. hormonal control
B. stimulus and response
C. balance
D. homeostasis