Answer:
A pie chart
Step-by-step explanation:
A pie chart would be the ideal type of chart to create this visual aid. A pie chart is simpler visually and easily understood. It can show data as portions or percentages of a whole. Since what they want is to present the different gases found in Earth's atmosphere, they can show what percentage of the different gases make up the atmosphere.
It is simpler because the size of each portion or "slice" of the pie chart itself can reveal a lot about the data without even reading the numbers.