There are many structural and thematic similarities between Piers Plowman by Langland (1330-1400) and House of Fame by Chaucer (1342-1400), two Middle English poems relating dream visions. Some critics have argued that because a number of the shared elements are uncommon in Middle English poetry, and because Langland' s poem probably predates Chaucer' s by a few years, Chaucer was most likely influenced by Piers Plowman when writing House of Fame. Which of the following, if true, most seriously weakens the critics' argument? ["Piers Plowman is one of Langland's major works, whereas House of Fame is a minor work of Chaucer's", 'Many of the themes and structures of Piers Plowman are also found in Latin, Italian, French works with which Chaucer could well have been familiar.', 'House of Fame survives in only three manuscript copies, substantially fewer than the number of manuscript copies that exist of Piers Plowman.', 'Because Piers Plowman became a well-known work in its day, it is likely that the similarities between it and House of Fame were detected by many of the people who read House of Fame soon after Chaucer wrote it.']