The answer is B: To identify what the author wants readers to do with the information in the article.
Restating an idea is repeating the same idea in different words and using a different structure. A reader may look for an idea that is restated because it shows that the author wanted to place a certain emphasis on that idea by repeating it. In this way, the reader can understand what was the objective of the author and what he/she wants the reader to do with the information in the article.
