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: Medicine
A 60 year old man presents with non productive cough for 4 weeks: He has grade I clubbing, and a lesion in the apical lobe on xray. Most likely diagnosis here is - 
Select and explain. 
A. Small cell ca, B. Non small cell ca, C. Fungal infection, D. Tuberculosis
B: Non small cell ca
Answer: B: Non small cell ca 
Explanation: None