This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Systemic histology, Subject name: Anatomy
[{'content': 'Anal transition zone is ? \nSelect and explain. \nA. columnar - cuboidal - squamous, B. columnar-squamous - cuboidal, C. squamous-cuboidal-columnar, D. cuboidal-squamous-columnar', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Anal transition zone is Columnar-Cuboidal-Squamous Dentate line (Pectinate line)is Sqaumocolumnar junction below to it is Squamous epithelium and above to it is transitional zone which is Columnar - Cuboidal epithelium.', 'role': 'assistant'}]