Answer:
Hello!
The answer is D) Homeostasis
Step-by-step explanation:
Homeostasis:
The regulation of a cell or an animal's internal environment in response to fluctuations in the external environment is called homeostasis.
Homeostasis is crucial to maintain an optimum environment for cell structures to work effectively.
In this case, the jackrabbiit's circulatory system is responding to fluctuating temperatures. In hot days, the body is at risk of heating up above optimum temperature which could hamper body functions. Therefore, the blood flow to the ears is increased to facilitate heat loss.
In cold temperatures, the blood flow to the ears is decreased to conserve heat for vital body organs. The blood flow is directed to the core of the body to protect the heart, lungs, liver and brain.