Expired air differs from inspired air in several ways: it contains more carbon dioxide, less oxygen, and more water vapor. Hence, the correct answer is all the above.
When we inhale, we take in air that is rich in oxygen and contains nitrogen, argon, carbon dioxide, and other gases in smaller amounts. The oxygen is used by our bodies for metabolism, a process that generates carbon dioxide as a waste product. Therefore, when we exhale, the air we release has a higher concentration of carbon dioxide.
Additionally, our bodies generate water vapor through respiration and other metabolic processes. This water vapor is exhaled as well, contributing to the higher moisture content in expired air compared to the drier inspired air. So, in summary, as we breathe in and out, the composition of the air changes significantly, which is why the correct answer includes all these differences.