This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
What are the buidling blocks for mostly lipids? 
Select and explain. 
A. Carbohydrates, B. Proteins, C. Fatty acid, D. None
C: Fatty acid
Answer: C: Fatty acid 
Explanation: The building blocks of most lipids are fatty acid.