This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Small & Large Intestine, Subject name: Surgery
Ca colon, investigation of choice is - 
Select and explain. 
A. CT scan, B. Ba enema, C. Colonoscopy, D. X-ray abdomen
C: Colonoscopy
Answer: C: Colonoscopy 
Explanation: Ans. is 'c' i.e., Colonoscopy * Colonoscopy with biopsy of suspect lesions is the gold standard test for establishing the diagnosis of CA colon.