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
Appropriate material for antenatal diagnosis of I genetic disorders includes all of the following except: 
Select and explain. 
A. Fetal blood, B. Amniotic fluid, C. Chorionic villi, D. Maternal urine
D: Maternal urine
Answer: D: Maternal urine 
Explanation: Maternal urine for prenatal diagnosis--an analysis of cell-free fetal DNA in maternal urine and plasma in the third trimester.