Which of the following is not true about body paragraphs? a. most paragraphs begin with a topic sentence. b. body paragraphs need to be indented. c. a good essay must have three body paragraphs. d. body paragraphs discuss topics directly related to the thesis statement.

The answer is C. A good essay can be as long as you want. It doesn't HAVE to be 3.

sentence lenght varies according to word choice.you select which word to use and that will require to use other expressions that collocate with the word chosen.sentence length will vary   according to the choice of words you make to express your ideas.