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: Microbiology
All of the following tumours are associated with organisms except: 
Select and explain. 
A. Gastric carcinoma, B. Hepatocellular carcinoma, C. Nasopharyngeal carcinoma, D. Non-small cell lung carcinoma
D: Non-small cell lung carcinoma
Answer: D: Non-small cell lung carcinoma 
Explanation: Non-small cell lung carcinoma