If the menstrual cycle is of 35 days then what is risk period (cycle start on `1^(st)` day) :-

Options

A. `9^(th)` to `17^(th)` days
B. `11^(th)` to `18^(th)`
C. `16^(th)` to `24^(th)` days
D. `18^(th)` to `35^(th)` days

Answer

To determine the risk period in a menstrual cycle of 35 days, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Menstrual Cycle**: The menstrual cycle is typically divided into two phases: the follicular phase and the luteal phase. Ovulation occurs approximately in the middle of the cycle.

2. **Identify the Ovulation Day**: In a 35-day cycle, ovulation typically occurs around the 16th or 17th day. This is because ovulation usually happens about 14 days before the start of the next menstrual period.

3. **Determine the Fertilization Window**: After ovulation, the ovum (egg) is available for fertilization for about 24 hours. Therefore, the risk period for fertilization starts on the day of ovulation and extends for 24 hours after.

4. **Calculate the Risk Period**:
- If ovulation occurs on the 16th day, the risk period would be from the 16th day to the 24th day of the cycle.
- If ovulation occurs on the 17th day, the risk period would still extend to the 24th day.

5. **Conclusion**: The risk period in a 35-day menstrual cycle is from the 16th to the 24th day.

### Final Answer:
The risk period for a 35-day menstrual cycle is from **16th to 24th day**.

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