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': 'Blood is of fetal origin in: \nSelect and explain. \nA. Placenta pre, B. Abruptio placentae, C. Vasa pre, D. Placenta accreta', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. C i.e. Vasa pre', 'role': 'assistant'}]