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
Test used to differentiate maternal from fetal blood 
Select and explain. 
A. Osmotic fragility test, B. Water bulb test, C. Apt test, D. Kleihauer Betke test
C: Apt test
Answer: C: Apt test 
Explanation: 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.