Answer:
The function of the circulatory system necessary for the respiratory system to complete the exchanges of gases in the body is red blood cells carrying oxygen away from the lungs (option D)
Step-by-step explanation:
The respiratory and circulatory systems are related because the supply of oxygen (O₂) to the entire body depends on them, in addition to allowing the expulsion of carbon dioxide (CO₂).
The function of the circulatory system that allows gas exchange in the body and contributes to respiratory function are the red blood cells, which carrying O₂ away from the lungs.
Red blood cells or erythrocytes contain a molecule, hemoglobin, which is responsible for transporting O₂ to the body and removing CO₂ from the tissues to be carried to the lungs for expulsion.
The other options are not correct because:
A and B. White blood cells are not in charge of transporting respiratory gases.
A and C. The exchange of gases does not occur directly to the atmosphere.