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: Medicine
[{'content': 'SIADH is associated with : \nSelect and explain. \nA. Small cell carcinoma lung, B. Adeno carcinoma lung, C. Squamous cell carcinoma lung, D. Mixed cell tumor lung', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Answer is A (Small cell Ca of lung): Small cell Ca of lung causes SIADH due to ectopic secretion of ADH.', 'role': 'assistant'}]