_________ are produced by yeast and act by competitively inhibiting the enzyme responsible for synthesis of cholesterol.

Options

A. Cyclosporin-A
B. Penicillin
C. Statins
D. Alcohol

Answer

To answer the question, "_________ are produced by yeast and act by competitively inhibiting the enzyme responsible for synthesis of cholesterol," we need to identify the correct term that fits in the blank.

### Step-by-Step Solution:

1. **Understanding the Question**: The question is asking for a substance that is produced by yeast and has the ability to inhibit the enzyme responsible for cholesterol synthesis.

2. **Identifying the Options**: The options provided include:
- Cyclosporine A
- Penicillin
- Statins
- Alcohol

3. **Evaluating Each Option**:
- **Cyclosporine A**: This is produced by the fungus *Trichoderma polysporum* and is known as an immunosuppressant. It does not relate to cholesterol synthesis. Therefore, this option is incorrect.
- **Penicillin**: This is an antibiotic and is not related to cholesterol synthesis. Thus, this option is also incorrect.
- **Statins**: These are compounds produced by the yeast *Monascus purpureus*. Statins are known to lower blood cholesterol levels by competitively inhibiting the enzyme responsible for cholesterol synthesis. This makes this option correct.
- **Alcohol**: This is not related to inhibiting cholesterol synthesis and is therefore incorrect.

4. **Conclusion**: After evaluating all options, the correct answer is **Statins**. They are produced by yeast and act by competitively inhibiting the enzyme responsible for cholesterol synthesis.

### Final Answer:
**Statins**