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': 'Type of early childhood caries in which labio-lingual extension of caries occurs involving incisors and /or molars is: \nSelect and explain. \nA. Type1 ECC, B. Type2 ECC., C. Type3 ECC., D. None.', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]