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
A patient presented with a 3.5 cms size lymph node enlargement, which was hard and present in the submandibular region. Examination of the head and neck did not yield any lesion. The next investigation to be done - 
Select and explain. 
A. Chest x ray, B. Triple endoscopy, C. Supravital oral mucosa staining, D. Laryngoscopy
B: Triple endoscopy
Answer: B: Triple endoscopy 
Explanation: None