Which statement correctly describes an example of homeostasis in humans?
1. the bones of the limbs provide leverage for movement.
2. the brain processes a separate image from each eye
3.the appendix has lost its digestive function over time
4. the kidneys remove excess water form blood.

4. The kidneys remove excess water from blood.

Explanation:

Homeostasis is the ability or quality of the body to regulate and maintain it's internal environment constant with respect to the changes occurring in the external environment. This makes the organism survive in the changing environment. Maintaining the temperature, pH, blood pressure, controlling the fluid balance all are example of the homeostasis.

The kidneys remove excess water from the blood along with the excess water many impurities and wastes are removed from the body by the process of urination. This way kidneys purifies the body by excreating wastes.  

the electromagnetic energy from the sun arrives in the form of visible and invisible light.

c. is the correct answer