Which of the following conditions are regulated by homeostasis?

1. temperature!

2. water levels!

3. cell waste!

4. all of the above!

Option 4 is the correct answer because the ability to maintain stable internal environment is known as homeostasis. However, the body keeps up (maintains) homeostasis for some factors including temperature. Moreover, water homeostasis in body is maintain through the ingested liquids which basically depends on thirst. The plasma membrane also keeps up (maintain) homeostasis by the regulation of useful materials within the cell.