Option 1 states that the average percentage of oxygen in the human body is 65%. This means that, on average, 65% of the human body is made up of oxygen. Option 2 suggests that the percentage is 25%, option 3 suggests it is 10%, and option 4 suggests it is 5% due to excess concentration of C02 in blood, lungs, or excess concentration of 02 in lungs. It is important to note that the correct answer provided is generally accurate, as oxygen does make up a significant portion of the human body. However, it should be noted that the exact percentage may vary among individuals and depending on various factors such as age, sex, and health.