Final answer:
A. pie chart is a graph that represents the divisions of a whole into proportional slices or sections. It's used to display the sizes of subgroups in relation to the entire group.
Step-by-step explanation:
The type of graph being described is known as a pie chart. A pie chart is a circular graph divided into slices to illustrate numerical proportion. In a pie chart, the entire circle represents the whole or total, and the slices represent parts of the whole, showing the relative sizes of subgroups.
It's a visual tool used to compare the parts of a whole and to convey data in an easily digestible graphical form. Pie charts are particularly useful for displaying data when there are a limited number of categories that add up to a total. However, they can become cluttered and hard to read when there are many small slices.