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: Anatomy
Watershed zone of large intestine ? 
Select and explain. 
A. Cecum, B. Ascending colon, C. Rectosigmoid, D. Transverse colon
C: Rectosigmoid
Answer: C: Rectosigmoid 
Explanation: There are areas of colon with poor blood supply resulting from incomplete anastomosis of marginal aeries. These are watershed areas of colon and include :Splenic flexure (Griffith point) : Watershed area between superior mesenteric aery and inferior mesenteric aery.Rectosigmoid junction (Sudeck's point) : Watershed zone between inferior mesenteric aery and internal iliac aery.