Concept:Inhaled and exhaled air have different compositions, but both contain oxygen.
Explanation:Inhaled air is the same as normal air. It contains about 21% oxygen, 78% nitrogen, 0.04% carbon dioxide, and trace gases.
Exhaled air still contains oxygen, but in a lower amount — roughly 16.4% oxygen, 4.4% carbon dioxide, and the rest nitrogen.
Thus, oxygen is present in both inhaled and exhaled air, only the percentage decreases.
Option B is correct. Options A, C, and D are false because both gases are present in both types of air.
Answer:B. Both inhaled air and exhaled air contain oxygen
