The correct answer is C. 0.12.
Exhaled air contains about 4% carbon dioxide, while inhaled air contains about 0.04% carbon dioxide. This means that the percentage of carbon dioxide in exhaled air is about 10 times higher than in inhaled air.
The increase in carbon dioxide in exhaled air is due to the fact that our bodies use oxygen to break down food molecules, releasing carbon dioxide as a waste product. This process is called cellular respiration.
The amount of carbon dioxide in exhaled air can vary depending on a number of factors, such as the person’s activity level, diet, and health status. For example, people who exercise vigorously will have a higher percentage of carbon dioxide in their exhaled air than people who are sedentary.
The percentage of carbon dioxide in exhaled air can also be used to monitor a person’s health. For example, people with diabetes may have a higher percentage of carbon dioxide in their exhaled air than healthy people.
Overall, the percentage of carbon dioxide in exhaled air is a useful indicator of a person’s health and well-being.