If Professor Wang is a teacher at Peking University [Weibo] and has written many philosophical articles, he must be a teacher in the Department of Philosophy. Which of the following, if true, would best support the above argument? ['Professor Wang has written many philosophical papers.', 'Philosophy teachers have written many philosophical papers.', 'Only teachers of the Department of Philosophy have written many philosophical papers among the teachers of Peking University.', 'Few teachers have written many philosophical papers.']