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': "One of the following is not true about vase pre: \nSelect and explain. \nA. Blood of maternal origin, B. May be a cause of antepaum hemorrhage, C. Blood of fetal origin, D. Singer's test positive", 'role': 'user'}, {'content': 'Answer: A \nExplanation: Blood of maternal origin', 'role': 'assistant'}]