Hemoglobin is a well-known example of a multimeric protein. What type of multimeric structure does it have, and why is this significant?

• A. Trimer; it allows for greater flexibility.
• B. Tetramer; it enables cooperative binding of oxygen.
• C. Dimer; it allows for increased stability.
• D. Monomer; it ensures efficient transport of oxygen.

Answer: (B)