Answer: Homeostasis
Explanation: The tendency of the body of an organism to maintain a constant internal environment inside the body which is known as homeostasis.
Homeostasis can be maintained by many factors inside the body. The concentration of pH, the temperature, the concentration of glucose are some of the examples by which the body maintains homeostasis.
The excretory system of the body filters and deals with the waste materials so that the body can maintain a suitable environment.