The purpose of a chart or graph is
a.) a reader visualize something.
b.) describe what is featured in an image.
c.) divide the parts of a text into logical units.
d.) present and summarize information.

A.) help a reader visualize something.

Explanation:

Information can be analyzed in various ways, the most common being reading. A useful tool for interpreting information, especially data, is graphics.

Charts consolidate information and give the reader a different reading approach. Charts can be of various types, colors and can depict the evolution of the analyzed item over time in a very subtle way.

the first question's answer is a.

answer; validity;