As per assembling a writing plan for an essay, the better answer, if not the best, would be B. Material that catches the reader's interest.
Many would argue that the correct answer would be D. the general idea of your essay or maybe C. a brief summary of your conclusion or perhaps A. the first section of the body of your essay. Well, they are all correct. As long as what follows is duly taken noted and is consistent to keep the flow of the essay that when the final paper is read, it isn't confusing in any way. Though generally speaking, what should come first would be the material that catches the reader's interest.
D - considering the audience
Answer:
1. The bike crashed into the house. (Fragment)
2. Crazy, pink flamingos flock together at the watering hole. (Fragment
3. (Leave it alone, complete sentence.)
4. (leave it alone, complete sentence.)
5. There are dirty footprints on the ceiling. (Fragment)
I gave a few sentence rewrites if you couldn't come up with any. Feel free to come up with your own if you don't like mine though. :)