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
First line investigation for esophageal carcinoma is: March 2004 
Select and explain. 
A. X-ray, B. Barium meal, C. Endoscopy, D. 24 hours pH measurement
C: Endoscopy
Answer: C: Endoscopy 
Explanation: Ans. C i.e. Endoscopy