Artists have different ways of producing contours and hatching, and analysis of these stylistic features can help to distinguish works by a famous artist both from forgeries and from works genuinely by other artists. Indeed, this analysis has shown that many of the drawings formerly attributed to Michelangelo are actually by the artist Giulio Clovio, Michelangelo' s contemporary. If the statements above are true, then which one of the following must also be true? ["The contour and hatching styles used to identify the drawings of Clovio cited can be shown to be features of all Clovio's works.", "There is an analyzable difference between Clovio's contour and hatching styles and those of Michelangelo.", 'Many of the drawings formerly attributed to Michelangelo are actually forgeries.', 'Contours and hatching are the main features that distinguish the drawing styles of different artists.']