The section presents a multiple-choice question regarding the composition of the Earth's atmosphere. It asks which element constitutes approximately 78% of the atmospheric volume. The options provided are:

A. Oxy (Oxygen)  
B. Nitơ (Nitrogen)  
C. Argon  
D. Carbon dioxide  

The key topic is the composition of the atmosphere, specifically focusing on the predominant gas. The correct answer is Nitrogen (B), which is the element that makes up about 78% of the atmosphere.