if you list each detail, you might as well just have the person reading the summary read the book. if you give them the length of the passage, that's useless because the length has nothing to do with the content of the story. your opinion won't help summarize it. therefore, the main idea is the correct option!
The information that belongs in a summary of a passage is:
The main idea of the passage
<h3>What is the summary of a passage?</h3>
The summary of a passage is the brief capturing of the main ideas of the passage. The summary is not meant to have a host of irrelevant materials or ideas rather, only the main points should be in the summary of the passage. Another vital point to note about a summary is the fact that it is supposed to be written in the words of the writer instead of that of the original writer.
This is not to say that the person who writes a summary should introduce new points that are not part of the things in the main text. Yet another factor to note about the summary of a passage is the fact that it is supposed to be brief. This means that the length of a summary should be less than the length of the main text.