The answer is b. Our body is made up of water and so we need to refresh our body from time to time by bringing more water in. The water in the air also helps us get oxygen. Plants take the water and sunlight to do photosynthesis which creates oxygen so we can breathe
Cholestrol streghtens the cell memebrane. Its STRUCTURE gets fixed in the cell membrane and then performs its FUNCTIONS that is to strengthen the cell membrane
