Answer:
The correct answer is C) proteins
Explanation:
The general formula of carbohydrates, lipids, and proteins are (CH2O)x, CH3(CH2)nCOOH, and RCH(NH2)COOH. It shows that carbohydrates, lipids, and proteins contain carbon, oxygen and hydrogen atom in them but only proteins have nitrogen atoms in it.
All proteins are made up of amino acids and all amino acids have nitrogen atom in the form of NH3 group. So metabolisms of amino acids are responsible for the formation of nitrogenous waste in organisms. In mammals, urea is the nitrogenous waste. So the correct answer is C.
