Answer: Hemoglobin
Explanation: Hemoglobin is a protein very rich in iron found in red blood cells and is responsible for the transportation of Oxygen from the lungs to the whole body. Oxygen binds to the hemoglobin in red blood cells and the red pigmentation of blood that is highly oxygenated is due to the hemoglobin content found in RBC's.
Erthyrocytes you can look this stuff up
It's responsible for motor control and balance and coordination of body and muscles.