Final answer:
An oxygen concentrator is a device that enriches room air with oxygen, making it the correct answer among the choices given. It provides a supply of oxygen by filtering ambient air, which is medically essential for people with certain respiratory conditions.
Step-by-step explanation:
Among the options provided, the machine that changes the air in a room into air with more oxygen is the C) Oxygen concentrator. An oxygen concentrator is a medical device that takes in air from the room and purifies it by removing nitrogen, thus providing air richer in oxygen. Unlike oxygen tanks, which contain a fixed amount of oxygen, concentrators can provide a continuous supply by filtering the surrounding air. This is essential for individuals who require medical oxygen due to conditions such as chronic obstructive pulmonary disease (COPD) and other respiratory illnesses.
During gas exchange, which occurs in the lungs' alveoli, oxygen flows from the air into the blood, and carbon dioxide flows from the blood into the air to be exhaled. This exchange is crucial for maintaining the body's respiratory and metabolic balance. In relation to other questions mentioned on organisms and respiratory systems, it's noted that organisms also produce carbon dioxide as they take in oxygen, and a setup to measure oxygen consumption would need a substance to absorb the produced carbon dioxide for accurate measurements.