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: Gynaecology & Obstetrics
[{'content': 'Commonest complication of mature treatoma is: \nSelect and explain. \nA. Torsion, B. Rupture, C. Haemorrhage, D. Malignancy', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Torsion', 'role': 'assistant'}]