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': 'In which off the follwing age group myelodysplastic syndromes (MDS) are most common - \nSelect and explain. \nA. 2-10., B. 15-20, C. 25-40, D. > 50 years', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]