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': 'All are essential unsaturated fatty acids except \nSelect and explain. \nA. Linoleic acid, B. Linolenic acid, C. Arachidonic acid, D. Palmitoleic acid', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Palmitoleic acid, oleic acid, linoleic acid, linolenic acid and arachidonic acid are the five unsatured fatty acids.\nAmong them palmitoleic acid, oleic acid are mono unsaturated fatty acids. linoleic acid, linolenic acid and arachidonic acid are essential unsaturated fatty acids.\nArachidonic acid becomes essential, if its precursor, linoleic acid is not present in the diet. It is considered as the precursor for the synthesis of prostaglondins.', 'role': 'assistant'}]