Which of the following is a valid statement? a. a research paper should rely most heavily on directly quoted material in order to avoid plagiarism and provide variety in syntax. b. an interesting research paper will include a variety of directly quoted and paraphrased sources and diverse sentence structures. c. if the outline is well-crafted, the researcher just needs to write one draft of the paper, as everything he/she needs will only have to be put together. d. the tone of a research paper requires a stilted, formal type of writing using only long, complex sentences to describe evidence from many sources.