In order to summarize a passage you should express the main ideas of the passage in your own. Option C is correct.
A summary is a short retelling of a longer written passage, which reflects the author’s most important ideas. Summarizing helps enhance both your reading and writing skills. To summarize, you must read a passage closely, detecting the main ideas and supporting ideas. Then you must briefly write down those ideas in a few sentences or a paragraph in your own words.