How do text features aid understanding of expository text?
a. they provide the main topic of the text.
b. they state the thesis sentence of the text.
c. they highlight and signpost key points of the text.
d. they suggest additional resources that will provide new information.

C. They highlight and signpost key points of the text.

Explanation:

In a story or an article all the components that are not the main body of text are what is known as text features, they help to highlight specific parts of the text like placing a table of contents, the index, or a glossary of terms; but also some features within the text like headings, bold words and the usage of sidebars. On the graphic side we can see as examples of text features pictures, captions and diagrams all of those help to signpost key points of the text.

the correct answer can either be a or b because it could be both but you should probally choose b