This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Physiology
Normal Brown colour of stool is due to 
Select and explain. 
A. Urobilin, B. Stercobilinogen, C. Stercobilin, D. Urobilinogen
C: Stercobilin
Answer: C: Stercobilin 
Explanation: Hemoglobin from RBC undergo metabolism and produces bilirubin and biliverdin. This, in turn, conveed into urobilinogen and stercobilinogen.This urobilin and stercobilin are responsible for giving colour to urine and stool respectively.During obstructive jaundice absence of this stercobilin leads to clay colored urine(Ref: Vasudevan, textbook of biochemistry)