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
[{'content': 'Fat in the duodenum lumen \nSelect and explain. \nA. Stimulates gall bladder contraction, B. Inhibits gall bladder contraction, C. Inhibits CCK secretion, D. Releases secretin', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Products of fat digestion (long chain fatty acids with more 10 carbon atoms) in the duodenum increase the secretion of CCK, the most potent hormone causing gallbladder contraction.', 'role': 'assistant'}]