Principle: Only if a professor believes a student knowingly presented someone else' s ideas without attribution should the professor make an official determination that the student has committed plagiarism. Application: It is not the case that Professor Serfin should make an official determination that Walters committed plagiarism in the term paper about Willa Cather that Walters wrote for Serfin' s class. Which one of the following, if true, justifies the above application of the principle? ["Although the main thesis of Walters's term paper is identical to that of a book that he did not cite, Professor Serfin is convinced that Walters did not knowingly try to pass anyone else's ideas off as his own.", "Professor Serfin does not have completely compelling evidence to conclude that Walters presented someone else's ideas as if they were his own in the term paper about Willa Cather.", 'Walters does not believe that Professor Serfin should make an official determination that he plagiarized.', 'If Walters had realized that the main thesis of his term paper is identical to the main thesis of a book he had read, Walters would have attributed the idea to the book.']