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
Without breast feeding the first menstrual usually begins - weeks after delivery : 
Select and explain. 
A. 2-4 weeks, B. 4-6 weeks, C. 6-8 weeks, D. 8-10 weeks
C: 6-8 weeks
Answer: C: 6-8 weeks 
Explanation: 6-8 weeks