_________ is another name for antibodies.

• A. Epitope.
• B. Immune protein.
• C. Antigen.
• D. Immunoglobulin.

Answer: (D)

Verified step by step guidance

1. Understand that antibodies are proteins produced by the immune system to identify and neutralize foreign objects like bacteria and viruses.
2. Recognize that antibodies are also known as immunoglobulins, which are glycoprotein molecules produced by plasma cells.
3. Differentiate between the terms: 'epitope' refers to the part of an antigen that is recognized by the immune system, 'immune protein' is a general term that could refer to various proteins involved in immune responses, and 'antigen' is a substance that induces an immune response.
4. Recall that the primary function of immunoglobulins (antibodies) is to bind to specific antigens to help protect the body from infections.
5. Conclude that the correct term for antibodies is 'immunoglobulin', as it specifically refers to the class of proteins that function as antibodies.