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
Easiest method of determining zygosity is : 
Select and explain. 
A. Blood grouping, B. Sex of fetus, C. Placental examination, D. Amniotic fluid examination
C: Placental examination
Answer: C: Placental examination 
Explanation: Placental examination