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: ENT
[{'content': 'Most common malignancy in maxillary Sinus is: \nSelect and explain. \nA. Squamous cell Ca, B. Muco-epidermal Ca, C. Adeno-cystic Ca, D. Adenbcarcinoma', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Malignant tumors of the nasal cavity and paranasal sinuses are rare, with poorly differentiated squamous cell carcinoma of the maxillary sinus being the most common.', 'role': 'assistant'}]