The example of a protein is

Options

A. Narvone
B. Lacithin
C. Cellulose
D. Insulin

Answer

### Step-by-Step Solution:

1. **Understanding Proteins**:
- Proteins are large biomolecules made up of chains of amino acids. They play crucial roles in the body, including structural support, transport, enzymes, and signaling.

2. **Amino Acids and Peptide Bonds**:
- Amino acids are the building blocks of proteins. They are linked together by peptide bonds to form a polypeptide chain, which then folds into a functional protein.

3. **Identifying Examples of Proteins**:
- To answer the question, we need to identify a specific example of a protein. Common examples include enzymes, antibodies, and hormones.

4. **Selecting the Correct Example**:
- Among various examples of proteins, insulin is a well-known protein hormone that regulates glucose levels in the blood.

5. **Conclusion**:
- Therefore, the correct answer to the question "The example of a protein is" is **insulin**.