What is the term for the cooperative binding of oxygen to the four subunits of hemoglobin, resulting in a sigmoidal oxygen-hemoglobin dissociation curve?

A Allosteric regulation
B Cooperative binding
C Hemoglobin polymerization
D Positive cooperativity ✓

Explanation

The cooperative binding of oxygen to hemoglobin refers to the phenomenon where the binding of one oxygen molecule to a subunit increases the affinity of the other subunits for oxygen, resulting in a sigmoidal oxygen-hemoglobin dissociation curve.

Source

Biochemistry textbook by Stryer
Hematology Hematology: Hemoglobin and Oxygen Transport Hematology: Hemoglobin and Oxygen Transport Hard MEDICAL Confidence: high