Which of the following natural method has nil chances of failing and has very least side effect?

Options

A. Periodic abstinence
B. Coitus interruptus
C. Lactational amenorrhea
D. Withdrawal method

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for a natural method of contraception that has a 0% chance of failure and minimal side effects.

2. **Evaluating the Options**:
- **Periodic Abstinence**: This method involves avoiding sexual intercourse during fertile days. However, it does not guarantee 0% chance of fertilization since mistakes can happen in tracking fertile days.
- **Coitus Interruptus**: Also known as the withdrawal method, this involves the male partner withdrawing before ejaculation. This method is not foolproof as pre-ejaculate fluid may contain sperm, leading to a possibility of fertilization.
- **Lactational Amenorrhea**: This method refers to the natural postpartum infertility that occurs when a woman is exclusively breastfeeding. It typically lasts for about 6 months after childbirth and during this time, the chances of ovulation and subsequent fertilization are significantly reduced.

3. **Identifying the Correct Answer**: Among the three methods evaluated, Lactational Amenorrhea stands out as it has a very low chance of failure (close to 0%) and minimal side effects during the breastfeeding period.

4. **Conclusion**: The method that has nil chances of failing and very least side effects is **Lactational Amenorrhea**.