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': 'Combination of ampicillin and gentamicin is an example of \nSelect and explain. \nA. Indifference, B. Synergy, C. Antagonism, D. Bacterial symbiosis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]