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
[{'content': 'Metabolically the most active of the plasma lipids is \nSelect and explain. \nA. Phospholipids, B. Cholesterol, C. Triacylglycerol, D. Free fatty acids', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Free fatty acids\xa0\n\nPlasma lipids consist of triacylglycerols (16%), phospholipids (30%), cholesterol (14%) and cholesteryl esters (36%), and a much smaller fraction of unesterified long chain fatty acids (4%). This latter fraction, the free fatty acids (FAA), is metabolically the most active of the plasma lipids.', 'role': 'assistant'}]