This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Head & Neck, Subject name: Pathology
[{'content': 'Cambium layer is seen in: \nSelect and explain. \nA. Embryonal rhabdomyosarcoma, B. Pleomorphic rhabdomyosarcoma, C. Alveolar rhabdomyosarcoma, D. Undifferentiated rhabdomyosarcoma', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) Embryonal rhabdomyosarcoma(Ref: Robbins 9th/pg 1253)In Sarcoma botryoides, a variant of embryonal rhabdomyosarcoma, histology shows a cambium layer where the tumors about the mucosa of an organ, they form a submucosal zone of hypercellularity.', 'role': 'assistant'}]