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
[{'content': 'Plasma levels of hCG during pregnancy doubles every: September 2010 \nSelect and explain. \nA. Daily, B. 2 days, C. 4 days, D. 6 days', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B: 2 days Pregnancy tests may be used to determine the bility of a pregnancy. Serial quantitative blood tests may be done, usually 2-3 days apa. Below an hCG level of 1,200 mIU/ ml the hCG usually doubles every 48-72 hours, though a rise of 50-60% is still considered normal. Failure to increase normally may indicate an increased risk of miscarriage or a possible ectopic pregnancy.', 'role': 'assistant'}]