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': 'Multifactorial causation of disease theory was proposed by ? \nSelect and explain. \nA. Louis pasteur, B. Pettenkofer, C. Robe koch, D. Aristotle', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Pettenkofer", 'role': 'assistant'}]