The correct answer is option 4: Interferon.

Option 1: Antibodies are proteins produced by the immune system in response to an infection. While antibodies play an important role in fighting off viral infections, they are not necessarily antiviral proteins themselves.

Option 2: Histones are proteins that help to package and organize DNA in the nucleus of cells. They are not directly involved in fighting off viral infections or acting as antiviral proteins.

Option 3: Nucleoproteins are proteins that are associated with DNA or RNA molecules and are involved in various cellular processes. Although some nucleoproteins may have antiviral properties, it is not a specific type of protein that is known for its antiviral activity.

Option 4: Interferons are a group of proteins that are released by cells in response to a viral infection. They play a crucial role in the immune response against viruses by inhibiting viral replication within infected cells and activating immune cells. Interferons have been studied and used as antiviral treatments for viral diseases, showing promise in the development of future treatments.

In conclusion, option 4 (Interferon) is the correct answer as it is a well-known antiviral protein that has potential in the development of