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
Minimum amount of GI bleed to cause melena is 
Select and explain. 
A. 10 ml, B. 40 ml, C. 60 ml, D. 115 ml
C: 60 ml
Answer: C: 60 ml 
Explanation: None