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': 'When two different chemicals act on two different receptors and their response is opposite to each other on the same cell, this is called as: \nSelect and explain. \nA. Physiological antagonism, B. Chemical antagonism, C. Reversible antagonism, D. Competitive antagonism', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]