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': 'Granules in the Corynebacterium diphtheria are called by following names, except \nSelect and explain. \nA. Metachromatic granules, B. Retractile granules, C. Babes Ernst granules, D. Volutin granules', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]