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': "Diene's phenomenon is seen in \nSelect and explain. \nA. Proteus, B. E.coli, C. Klebsiella, D. Mycoplasma", 'role': 'user'}, {'content': "Answer: A \nExplanation: Diene's phenomenon - proteus\nDiene's method of staining\xa0→ mycoplasma", 'role': 'assistant'}]