What is the structural composition of hemoglobin?

• A. Hemoglobin is a monomeric protein with one subunit.
• B. Hemoglobin is a trimeric protein with three subunits.
• C. Hemoglobin is a heterotetrameric protein with four subunits.
• D. Hemoglobin is a dimeric protein with two identical subunits.

Answer: (C)