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 of the following are essential aminoacids except: \nSelect and explain. \nA. Methionine, B. Lysine, C. Alanine, D. Leucine', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Threonine, Lysine, Phenylalanine, Methionine, Isolcucine & Leucine, Tryptophan, Valine > Histidine >> Arginine are nutritionally essential amino acids. Among these last two (histidine & arginine) are semi- essential, and arginine is more essential than histidine.', 'role': 'assistant'}]