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: Surgery
Commonest cancer of the oral cavity is - 
Select and explain. 
A. Adenocarcinoma, B. Melanoma, C. Sarcoma, D. Squamous cell carcinoma
D: Squamous cell carcinoma
Answer: D: Squamous cell carcinoma 
Explanation: None