Select the best example of homeostasis from the choices below.
- when muscle cells need more oxygen, heart rate increases to pump blood faster.
- when plants do not get enough water, their vacuoles shrink and plants wilt.
- technology can a person to breathe when they cannot get enough oxygen on their own.
- bacteria live inside the digestive organs of animals, often supplying them with essential nutrients.

Option A

Explanation:

Homeostasis can be defined as the condition in which the body maintains the equilibrium inside the body with respect to the changing environment.

Maintaining the adequate amount of oxygen in the body is also a part of homeostasis.

When the oxygen level in the body goes below normal then the heart rate of the body increases. This supplies more oxygen and the level in the body is maintained.

This condition is an example of homeostasis in the human body.