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: Pharmacology
[{'content': 'In which of the following phases of clinical trials, healthy normal human volunteers participate: \nSelect and explain. \nA. Phase–I, B. Phase–II, C. Phase–III, D. Phase–IV', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]