Main Ideas are mostly found at the beginning of the paragraphs. They are the most discussed subject in the topic.
Answer:
in my opinion C. section headings
Explanation:
that is because italic is not as good at grouping info, illustrations well I'm not sure about that one, diagrams is more of giving a visual of the groups but in writing that is not as handy as headings to clarify what you are reading.
Answer:
Make the more important items your general topics.
By author is the only way.......