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
In the perspective of the busy life schedule in the modern society, the accepted minimum period of sexual cohabilitation resulting in no offspring for a couple to be declared infertile is: 
Select and explain. 
A. One year, B. One and a half - year, C. Two years, D. Three years
A: One year
Answer: A: One year 
Explanation: If a couple fails to achieve pregnancy after one year of “unprotected” and regular intercourse, it is an indication to investigate the couple for infertility.
• Infertility:
– Primary : When no previous pregnancies have occurred.
– Secondary : When a prior pregnancy although not necessary although not necessary a live birth, has occurred.