In ability to conceive or produce children ever after _____ of unprotected sexual cohabitation is called infertility.

Options

A. one month
B. six months
C. one year
D. two years

Answer

To solve the question, we need to fill in the blank regarding the definition of infertility. The question states: "Inability to conceive or produce children ever after _____ of unprotected sexual cohabitation is called infertility."

### Step-by-Step Solution:

1. **Understanding Infertility**: Infertility is defined as the inability to conceive after a certain period of regular unprotected sexual intercourse.

2. **Identifying the Time Frame**: The question requires us to determine the specific duration after which infertility is diagnosed.

3. **Evaluating Options**:
- **Option 1**: One month - This is generally too short a time frame to diagnose infertility.
- **Option 2**: Six months - This is also considered too short for a definitive diagnosis of infertility.
- **Option 3**: One year - This is the standard medical definition for infertility.
- **Option 4**: Two years - While this is longer than the standard, it is not the typical definition.

4. **Conclusion**: Based on the evaluation, the correct answer is **one year**. Therefore, the complete statement reads: "Inability to conceive or produce children ever after **one year** of unprotected sexual cohabitation is called infertility."

### Final Answer:
**One year**