This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of lipid, Subject name: Biochemistry
[{'content': 'Which of the following is a polyunsaturated fatty acid? \nSelect and explain. \nA. Palmitic acid, B. Stearic acid, C. Oleic acid, D. Linoleic acid', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Three polyunsaturated fatty acids, linoleic acid, linolenic acid and arachidonic acid are called "essential fatty acids" (EFA). They cannot be synthesised in the body and must be provided in the diet. Lack of EFA in the diet can produce growth retardation and other deficiency manifestation symptoms.Ref: Textbook of Medical Biochemistry, Eighth Edition, Dr (Brig) MN Chatterjea, page no: 48', 'role': 'assistant'}]