Hey can someone please help will mark brainliest

A mechanical ventilator in a hospital is designed to assist in breathing. It will deliver oxygen-
carbon dioxide balanced air to the patient at a prescribed rate. Why is carbon dioxide included in
this mixture?
of
Select one:
O a. Carbon dioxide stimulates the medulla oblongata in the brain.
O b. Pure oxygen causes the formation of nitrogen bubbles in the blood.
O c. Pure oxygen cannot be absorbed by the lungs unless diluted with other gases.
O d. Carbon dioxide is necessary to reduce the breathing rate of the patient.