Final answer:
Homeostasis is the body's ability to maintain a stable internal environment. Examples of homeostasis include sweating to cool the body and shivering in response to cold.
Step-by-step explanation:
Homeostasis is the body's ability to maintain a stable internal environment despite external changes. A) Sweating to cool the body is an example of homeostasis because it helps regulate body temperature. When the body gets too hot, sweat glands release sweat, which evaporates and cools the skin.
Another example of homeostasis is C) Shivering in response to cold. Shivering is a reflex that generates heat to raise body temperature when it drops too low. The muscles contract rapidly, generating heat in the process.
B) Rapid heartbeat during exercise is not an example of homeostasis. When we exercise, the heart rate increases to deliver more oxygen and nutrients to the muscles.
D) Increased hunger after fasting is not an example of homeostasis, but rather a response to a decreased food intake. When we fast, our body responds by increasing hunger to encourage us to eat and restore our energy levels.