In the perspective of the busy life schedule in the modern society, the accepted minimum period of sexual co-habitation resulting in no offspring for a couple to be declared as infeile is:
**Core Concept**
Infertility is a condition where a couple is unable to conceive after a certain period of unprotected sexual intercourse. The **World Health Organization (WHO)** defines infertility as the inability to conceive after 12 months of regular, unprotected sexual intercourse.
**Why the Correct Answer is Right**
The correct answer is based on the definition of infertility by the **WHO**, which states that a couple should have regular, unprotected sexual intercourse for at least 12 months before being considered infertile. This period allows for the natural variability in human reproduction and accounts for factors such as **ovulation cycles** and **sperm quality**.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it is too short a period, and many couples may take several months to conceive due to natural variability.
**Option B:** This option is also incorrect, but closer to the correct answer, it still does not meet the **WHO** criteria.
**Option D:** This option is incorrect because it is too long, and couples may be experiencing infertility issues that need to be addressed sooner.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that the definition of infertility can vary depending on the age of the female partner, with older women having a shorter window for conception due to **declining egg quality**.
**Correct Answer:** C. 12 months