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
Commando operation is used as treatment for 
Select and explain. 
A. Colon cancer, B. Carcinoma esophagus, C. Parotid gland tumour, D. Carcinoma of oral cavity
D: Carcinoma of oral cavity
Answer: D: Carcinoma of oral cavity 
Explanation: None