This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General obstetrics, Subject name: Gynaecology & Obstetrics
[{'content': 'Absolute proof of monozygosity is determined by \nSelect and explain. \nA. DNA finger printing, B. Intervening membrane layers, C. Sex of the babies, D. Reciprocal skin grafting', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Zygosity refers to the type of conception and can only be determined by DNA testing. Refer page no 179 of Text book of obstetrics,sheila balakrishnan,2 nd edition.', 'role': 'assistant'}]