According to the passage, which of the following statements best

According to the passage, which of the following statements best describes the function of illustrations in exposition?
A、Illustrations are primarily used to entertain readers.
B、Illustrations are utilized to summarize the main points of the essay.
C、Illustrations serve to support or develop the ideas discussed in the text.
D、Illustrations are solely employed to criticize opposing viewpoints.
【正确答案】:C