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
Levels of progesterone indicating unble pregnancy and ble intrauterine pregnancy are: 
Select and explain. 
A. 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
A: 5 ng/ml; 20 ng/ml
Answer: A: 5 ng/ml; 20 ng/ml 
Explanation: 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.