This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pharmacology
The amount of blood lost in GIT to produce a single black stool is approximately(NOT REALTED-SURGERY) 
Select and explain. 
A. < 20 ml, B. 30-40 ml, C. 60-70 ml, D. 100-110 ml
C: 60-70 ml
Answer: C: 60-70 ml 
Explanation: Approximately 60 ml of blood is required to produce a single black stool