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': 'Enamel is soft and acid insoluble in routine preparation after formalin fixation if : \nSelect and explain. \nA. Hypomineralized., B. Hypoplasia., C. In both Cases., D. Never become soft.', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]