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: Social & Preventive Medicine
[{'content': 'Commonest complication following intra uterine device inseion is: \nSelect and explain. \nA. Bleeding, B. Pain, C. Pelvic infection, D. Uterine perforation', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The commonest complication following IUD inseion is increased vaginal bleeding. Greatest blood loss is caused by larger non medicated devices. Ref: Park, 22nd edition pg: 459', 'role': 'assistant'}]