The best personal essays are organized into: a. an introduction, a body, and a conclusion. b. three different ideas. c. five paragraphs. d. three- to five-page papers.

Explanation:

Option A is always the answer among these options. Having three different ideas to right a personal essay is against writing rules, because it will be easy to lose the main purpose of the essay, readers will be lost. At the same time, setting the number of pages or paragraphs is not a way to organise the information, because you can write a ten pages essay, but if the ideas are not punctual and organized, reader won't know even what's about.

On the other hand, setting an introduction, a body and a conclusion is the right way to organize the essay, because your are establishing correctly each stage of it. A good writing is when you have ideas clear, and you introduce,  explain and close those ideas.

that is correct.