The correct answer is D. A circle graph
Step-by-step explanation:
Circle graphs are ideal to show the proportions of a whole. For example, the types of flowers found in an ecosystem. This is because circle graphs visually display all the parts that compose a population, phenomenon, etc. and the percentage of each, which are represented as proportions in a circle.
This would be ideal for Kenton because through this type of graph he can include all the chemical components of air and show appropriately the percentage or proportion of each. Also, other graphs do not fit Kenton's purpose; for example, line graphs are used to show change over time, and box-and-whisker plots are used to show factors such as the median of collected data.