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: Microbiology
[{'content': 'The sulphur granules in the wound are diagnostic of: \nSelect and explain. \nA. Nocardia, B. Actinomyces, C. Clostridium welchii, D. Aspergillus flavum', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Actinomyces', 'role': 'assistant'}]