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 Supra basal layer of masticatory mucosa has express Cytokeratin type: \nSelect and explain. \nA. Type CK1 and 13., B. Type CK1 and 10., C. Type CK2 and 13., D. Type CK2 and 10.', 'role': 'user'}, {'content': 'Answer: B \nExplanation: About 20 types of cytokeratin are recognized. They can\xa0be classified into two main types: type I (basic cytokeratins)\xa0and type II (acidic cytokeratins). They have been assigned\xa0numbers: type I (1-8) and type II (9-20). Cytokeratins\xa0always occur in pairs of combination of type I with type II.\xa0In the absence of its pair they are unstable and are susceptible to degradation by proteases. Cytokeratin profile reflects both cell type and differentiation status in different\xa0types and different layers of epithelia. For example, the\xa0suprabasal layers of masticatory mucosa express CK1 and\xa010, whereas CK4 and 13 are expressed by suprabasal cells\xa0of lining mucosa.', 'role': 'assistant'}]