Which gases significantly compose Earth's atmosphere?

The composition of Earth's atmosphere is primarily defined by a mixture of several gases, with nitrogen and oxygen being the most abundant. Nitrogen accounts for about 78% of the atmosphere, while oxygen makes up approximately 21%. Argon is a noble gas that constitutes about 0.93% of the atmosphere, and carbon dioxide, although present in smaller amounts (around 0.04%), plays a crucial role in processes such as photosynthesis and climate regulation.

Choosing the option that includes nitrogen, oxygen, argon, and carbon dioxide accurately reflects the major components of the atmosphere. This understanding is essential because each of these gases contributes differently to various atmospheric processes and environmental phenomena. The significance of each component highlights the complexity and balance of Earth's atmospheric composition, which is vital for sustaining life and influencing weather patterns.

The other options either exclude key components of the atmosphere or include gases that are not significant in terms of their abundance or role in Earth's atmospheric system. For example, while oxygen and carbon dioxide are important, the absence of nitrogen and argon in those choices does not represent the full picture of atmospheric composition. Similarly, hydrogen and methane are not major components of the atmosphere and are present in minuscule amounts compared to the gases listed in the correct answer