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': "Which of the following is true of 'placebo' ? \nSelect and explain. \nA. Placebo is a dummy medication, B. Placebo is the inert material added to the drug for making tablets, C. Placebos do not produce any effect, D. All patients respond to placebo", 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]