How do pills work?
A. Inhibit ovulation and implantation
B. Alter the quality of vervical mucus to prevent or retard the entry of sperms
C Prevent the ejaculated semen from entering the female vagina
D. Inhibit spermatogenesis

Options

A. B and C
B. A and B
C. A and D
D. C and D

Answer

To answer the question "How do pills work?" we need to analyze the options provided and understand the mechanisms of oral contraceptive pills.

### Step-by-Step Solution:

1. **Understanding the Purpose of Pills**:
- Oral contraceptive pills are primarily used to prevent pregnancy. They can be taken regularly or used as emergency contraception within 72 hours after unprotected intercourse.

2. **Evaluating Option A**:
- **Inhibit ovulation and implantation**:
- Oral pills work by preventing ovulation (the release of an egg from the ovary) and making the uterine lining less suitable for implantation. This means that if fertilization occurs, the fertilized egg is less likely to implant in the uterus. This option is a correct mechanism of how pills work.

3. **Evaluating Option B**:
- **Alter the quality of cervical mucus to prevent or retard the entry of sperm**:
- Oral contraceptive pills also thicken the cervical mucus, making it more difficult for sperm to enter the uterus. This is another correct mechanism of action for the pills.

4. **Evaluating Option C**:
- **Prevent the ejaculated semen from entering the female vagina**:
- This option is incorrect because the action of oral contraceptive pills does not involve preventing semen from entering the vagina. This is not a function of the pills.

5. **Evaluating Option D**:
- **Inhibit spermatogenesis**:
- This option is also incorrect because spermatogenesis is the process of sperm production in males, and oral contraceptive pills do not affect this process.

6. **Conclusion**:
- Based on the evaluations, the correct answers are options A and B. Both mechanisms are involved in how oral contraceptive pills work to prevent pregnancy.

### Final Answer:
The correct options are A (Inhibit ovulation and implantation) and B (Alter the quality of cervical mucus to prevent or retard the entry of sperm).

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