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': 'The most common cause of euvolemic hyponatremia is which of the following? \nSelect and explain. \nA. Hypothyroidism, B. Hypoadrenalism, C. Hypehyroidism, D. SIADH', 'role': 'user'}, {'content': 'Answer: D \nExplanation: The syndrome of inappropriate antidiuresis is the most common cause of euvolemic hyponatremia. Reference: Harrisons Principles of Internal Medicine, 18th Edition, Page 345', 'role': 'assistant'}]