Question

composition of air
nitrogen - 78%
oxygen - 20.9%
other gases - >0.17%
argon - >0.90%
carbon dioxide - 0.03%
the atmosphere is mostly
○ carbon dioxide
○ oxygen
○ argon
○ nitrogen

Explanation:

Step1: Check the pie chart data

The chart shows Nitrogen at 78%, the largest percentage.

Step2: Match with options

78% is the highest proportion, so Nitrogen is the most abundant.

Answer:

D. nitrogen