The interferons are:

Options

A. Artibacterial proteins
B. Antiviral proteins
C. Immunosuppressive drugs
D. Antibiotics

Answer

### Step-by-Step Solution:

1. **Understanding Interferons**: Interferons are proteins produced by animal cells in response to viral infections. They are part of the immune response and play a crucial role in defending against viruses.

2. **Function of Interferons**: When a cell is infected by a virus, it produces interferons that act as signaling molecules. These molecules help to warn neighboring cells about the viral infection.

3. **Mechanism of Action**: Interferons stimulate neighboring cells to produce biochemicals that inhibit viral replication. This means that they help to prevent the virus from spreading to other cells.

4. **Classification of Interferons**: Interferons are specifically categorized as antiviral proteins because their primary function is to combat viral infections.

5. **Eliminating Incorrect Options**:
- **Antibacterial Proteins**: These work against bacteria, not viruses.
- **Immunosuppressive Drugs**: These reduce the immune response, which is contrary to the action of interferons.
- **Antibiotics**: These are substances that kill or inhibit bacteria, not viruses.

6. **Conclusion**: Based on the functions and characteristics of interferons, the correct classification is that they are **antiviral proteins**.

### Final Answer:
Interferons are **antiviral proteins**.

---