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
Most important stimulant for bile secretion is 
Select and explain. 
A. Cholecystokinin, B. Secretin, C. Bile acid, D. Bile salt
D: Bile salt
Answer: D: Bile salt 
Explanation: Bile salts are the most important cholerectic or the substance that increases bile secretion. Cholecystokinin (CCK) is the most important cholagogue or substance that increases gallbladder contraction.