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': 'Trace element not needed is - \nSelect and explain. \nA. Chromium, B. Molybdenum, C. Magnesium, D. Cesium', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]