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': 'Levels of progesterone indicating unble pregnancy and ble intrauterine pregnancy are: \nSelect and explain. \nA. 5 ng/ml; 20 ng/ml, B. 10 ng/ml; 20 ng/ml, C. 5 ng/ml; 50 ng/ml, D. 10 ng/ml; 50 ng/ml', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Serum progesterone concentration <5 ng/ml suggest a dying pregnancy Level > or = 20 ng/ml suppo the diagnosis of a healthy pregnancy. Ref: Williams Obs 24e pg 355.', 'role': 'assistant'}]