Earth's atmosphere is composed primarily of which percentages?

• A. 78% Nitrogen, 21% Oxygen, 1% everything else
• B. 78% Oxygen, 21% Nitrogen, 1% Argon
• C. 80% Nitrogen, 15% Oxygen, 5% Others
• D. 75% Nitrogen, 25% Oxygen, 0% others

Answer: (C)