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: Dental
[{'content': 'The consistency of the subgingival calculus is described to be: \nSelect and explain. \nA. Clay like, B. Flint like, C. Brick like, D. Soft', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]