This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Placenta and Chorion Development, Subject name: Gynaecology & Obstetrics
[{'content': 'Normal weight of term placenta in gms - \nSelect and explain. \nA. 300, B. 500, C. 700, D. 1000', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. is \'b\' i.e., 500 "The placenta at term is almost circular disk with a diameter ofl5-20cms & thickness of about 3 cms at its centre5. It thins towards the edge. It feels spongy & weighs about 500gmsf the proportion of the weight of the baby being roughly 1:6 at term and occupies the 30% of the uterine wall "', 'role': 'assistant'}]