This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Gynaecology & Obstetrics
[{'content': 'Test used to differentiate maternal from fetal blood \nSelect and explain. \nA. Osmotic fragility test, B. Water bulb test, C. Apt test, D. Kleihauer Betke test', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The Apt test is most commonly used in cases of vaginal bleeding late during pregnancy (antepaum haemorrhage) to determine if the bleeding is from the mother or the fetus.', 'role': 'assistant'}]