What is the primary function of the hemoglobin molecule in the blood?

A To regulate blood pressure
B To transport oxygen from the lungs to the tissues ✓
C To regulate body temperature
D To aid in the digestion of nutrients

Explanation

Hemoglobin is a protein in red blood cells that carries oxygen from the lungs to the body's tissues and returns carbon dioxide from the tissues back to the lungs.

Source

Guyton and Hall Textbook of Medical Physiology
Hematology Hematology: Hemoglobin and Oxygen Transport Hematology: Hemoglobin and Oxygen Transport Easy MEDICAL Confidence: high