A vasectomy-

Options

A. prevents the production of sperm in the testes
B. prevents the production of semen
C. prevents the movement of sperm into the urethra
D. prevents a man from having an erection

Answer

**Step-by-Step Solution:**

1. **Understanding Vasectomy**: A vasectomy is a surgical procedure performed on males for the purpose of sterilization or permanent contraception. It involves cutting or blocking the vas deferens, which are the tubes that carry sperm from the testes to the urethra.

2. **Analyzing the Options**:
- **Option A**: Prevents the production of sperm in the testes - This is incorrect because sperm production continues even after a vasectomy; only the transport of sperm is affected.
- **Option B**: Prevents the production of semen - This is also incorrect as semen production continues; it is only the sperm that cannot reach the urethra.
- **Option C**: Prevents the movement of sperm into the urethra - This is correct because the vas deferens is cut or blocked, preventing sperm from entering the urethra.
- **Option D**: Prevents a man from having an erection - This is incorrect; a vasectomy does not affect a man's ability to have an erection.

3. **Conclusion**: The correct answer is Option C, which states that a vasectomy prevents the movement of sperm into the urethra. This is achieved by cutting or tying the vas deferens, which stops sperm from being included in the semen that is ejaculated.

4. **Functionality of Vasectomy**: After a vasectomy, sperm are still produced in the testes but cannot travel through the vas deferens to mix with semen. This means that even after sexual intercourse, fertilization cannot occur as sperm are not present in the ejaculate.