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
Most common malignancy in maxillary Sinus is: 
Select and explain. 
A. Squamous cell Ca, B. Muco-epidermal Ca, C. Adeno-cystic Ca, D. Adenbcarcinoma
A: Squamous cell Ca
Answer: A: Squamous cell Ca 
Explanation: 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.