Answer: The correct answer is Option d.
Explanation:
Dry air is composed of a mixture of gases like argon, oxygen, nitrogen, carbon dioxide and many other gases present in trace amount.
The percentage of these gases by volume in dry air is:
Carbon dioxide = 0.03%
Argon = 0.93%
Oxygen = 20.95%
Nitrogen = 78.09%
Hydrogen = Trace amounts
From the above percentage values, we can easily say that nitrogen has the highest percentage by volume in dry air. Hence, the correct option is d.