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: Social & Preventive Medicine
[{'content': 'Conditionally Essential amino acids are \nSelect and explain. \nA. Tyrosine & Cysteine, B. Histidine & Arginine, C. Leucine & Lysine, D. Phenylalanine & Tryptophan', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Conditionally Essential Amino Acids (CEAA):\nNon-essential amino acids may turn essential if their precursors are\xa0limited in the body\n– There are 2 CEAA, namely, Tyrosine (derived from Phenyalanine) and Cyteine (derived from methionine)', 'role': 'assistant'}]