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: Physiology
Rennin is present in ? 
Select and explain. 
A. Gastric juice, B. Liver, C. Kidney, D. Lung
A: Gastric juice
Answer: A: Gastric juice 
Explanation: Ans. is 'a' i.e., Gastric juice [Ref: Principal of Medical physiology p. 786Rennin (also called chymosin) is a proteolytic enzyme is found in gastric juice. It is synthesized by chief cells in the stomach.