Answer:
A. Condense the author's idea into a shortened version but in your own words
Step-by-step explanation:
D. Take an author's idea word for word from the text is plagiarism, unless you are are quoting. C. Rewriting the author's idea in your own words in a version that is about the same length is paraphrasing. A. is the definition of summarize. When someone asks you to "sum up" a story, they are asking you to give you a shorter version of the story with only the most important parts. Paraphrasing and summarizing sound pretty similar, but the key difference is in length. A paraphrase should be about the same length as the original idea, summarizing should be shorter. B. is also wrong, since you are expanding upon the author's thoughts, when summarizing tries to condense them.