Answer:
The answer is: Mix topics, sentences, and paragraphs in an outline.
Step-by-step explanation:
An outline should be organized and neat, listing supporting ideas and major points is a must. It should give you the essential features of something, but not in detail, this is the reason why the three first options aren't possible, as them three need to be included. As it should be organized and concise; mixing topics and "paragraphs" in an outline is the worst practice you could do.