How do overviews and summaries when working with difficult texts?

a.) they make reading the text unnecessary.
b.) they provide questions that will be on a test.
c.) they readers prepare for and monitor their reading.
d.) they determine what information comes next.

C.) They help readers prepare for and monitor their reading.

Explanation: For sure summaries and overviews do not replace the complete texts, however, they are a good way of getting ready and monitoring. This means that if the complete text is too difficult to make sense at once, it can be uselful for the reader to have a look at a summary or an overview to have an idea of what the text is about and find the general meaning of it.