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
The peak level of chorionic gonadotropin in normal pregnancy occurs at : 
Select and explain. 
A. 30 -- 40 days, B. 60 -- 70 days, C. 10 -- 20 days, D. 100 -- 110 days
B: 60 -- 70 days
Answer: B: 60 -- 70 days 
Explanation: 60 -- 70 days