In physiology, we use the term "sink" to describe a structure responsible for the removal of some substance. So for instance, because the kidneys remove acid and waste from the body, we could refer to the kidneys as an "acid-sink" or "waste-sink". Additionally, because our integumentary system(skin) removes heat from our bodies, the skin could be referred as a "heat-sink". Using this term sink, which of the following would be correctly stated? A the cells are an "02-sink" and the lungs are a "CO2-sink" B the cells are "CO2-sink" and the lungs are an "O2-sink" C the cells are a "waste-sink" and the lungs are an "O2-sink" D all of the above are correct E none of the above are correct