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': 'True about hCG is : \nSelect and explain. \nA. Alfa subunit identical to LH, FSH and TSH, B. Causes involution of corpus luteum, C. Doubles in 7-10 days, D. Maximum level seen at 50 days of gestation', 'role': 'user'}, {'content': 'Answer: A \nExplanation: hCG is a glycoprotein with high sialic acid content. It bears a close structural similarity to the other glycoprotein hormones (FSH, LH, and TSH) all of whose alpha subunits are identical. It rescues and maintains corpus luteumtill 6 weeks of pregnancy. doubling time is 1.4-2days. maximum levels reach between 60-70 days of pregnancy. Reference: Dutta Textbook of Obstetrics 7th edition page 58', 'role': 'assistant'}]