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
The area of the colon which is least visualized by barium studies - 
Select and explain. 
A. Sigmoid, B. Hepatic flexure, C. Splenic flexure, D. Caecum
A: Sigmoid
Answer: A: Sigmoid 
Explanation: None