This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gastrointestinal System, Subject name: Physiology
[{'content': 'Which of the following is the strongest cholagogue? \nSelect and explain. \nA. Vagus nerve/Ach, B. Cholecystokinin, C. Bile acids, D. Secretin', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Cholagogues are the substances that increase the bile flow by causing gall bladder contraction. CCK is a cholagogue. Vagus nerve, bile acids are choleretics; they increase the bile secretion from liver.', 'role': 'assistant'}]