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': 'A patient presents at 28 weeks gestation with severe abdominal pain, bleeding and hypeension. The most likely diagnosis is : \nSelect and explain. \nA. Placenta pre, B. Accidental hemorrhage, C. Vasa pre, D. Rupture of ectopic pregnancy', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Accidental hemorrhage', 'role': 'assistant'}]