The only birth control that is 100% effective:

Options

A. Abstinence
B. Natural family planing
C. Birth Control pills
D. Emergency contraceptive

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the only birth control method that is 100% effective.

2. **Reviewing the Options**: The options provided are:
- Abstinence
- Natural Family Planning
- Birth Control Pills
- Emergency Contraceptives

3. **Analyzing Abstinence**: Abstinence means refraining from sexual intercourse. If there is no sexual activity, there is no possibility of sperm meeting an egg, making this method 100% effective in preventing pregnancy.

4. **Analyzing Natural Family Planning**: This method involves tracking the menstrual cycle to avoid intercourse during the ovulation window. However, since ovulation can be unpredictable, this method is not 100% effective.

5. **Analyzing Birth Control Pills**: Birth control pills contain hormones that prevent ovulation. While they are effective, they are not foolproof due to potential human error in taking the pills or hormonal imbalances, thus not guaranteeing 100% effectiveness.

6. **Analyzing Emergency Contraceptives**: These are taken after unprotected intercourse to prevent pregnancy. They are effective but not 100% guaranteed, especially if taken outside the recommended time frame.

7. **Conclusion**: After analyzing all the options, it is clear that the only method that guarantees 100% effectiveness in preventing pregnancy is **Abstinence**.

**Final Answer**: The only birth control that is 100% effective is **Abstinence**.

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