A woman uses pills A to prevent pregnancy for birth control. These pills prevent the ovaries from releasing ovum into oviducts. Another woman uses a chemical B that kills the sperm and prevent pregnancy.
The chemical B is :

Options

A. Antidepressants
B. Sedatives
C. Spermicides
D. Hormones

Answer

To solve the question regarding the chemical B that kills sperm and prevents pregnancy, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Context**:
- The question states that one woman uses pills A to prevent pregnancy by stopping ovulation. This indicates that these pills are hormonal contraceptives that prevent the ovaries from releasing an ovum.

2. **Identifying Chemical B**:
- The second woman uses a chemical B that kills sperm. We need to identify what type of chemical is used for this purpose.

3. **Analyzing the Options**:
- The options provided in the video transcript include:
- Anti-depressants
- Sedatives
- Spermicides
- Hormones

4. **Eliminating Incorrect Options**:
- **Anti-depressants**: These are medications that affect the central nervous system and are used to treat depression. They do not relate to birth control.
- **Sedatives**: These are used to calm the brain and induce sleep, not for preventing pregnancy.
- **Hormones**: Hormonal pills (like the ones in pills A) are used for birth control but do not kill sperm.

5. **Identifying the Correct Answer**:
- **Spermicides**: These are chemicals specifically designed to kill sperm and prevent fertilization. Therefore, chemical B that kills sperm is a spermicide.

6. **Conclusion**:
- The correct answer to the question is that chemical B is a **spermicide**.

### Final Answer:
Chemical B is a **spermicide**.