The local fair held its annual photography contest and accepted entries from both amateurs and professionals. The contest awarded prizes in each of several categories. As it turned out, most of the prizes in the contest were won by amateurs. Each of the following, if true, could by itself constitute an explanation of the outcome of the photography contest EXCEPT: ['Amateurs tend to enter their best photographs while professionals tend to save their best work for their clients.', 'Three times as many amateurs entered the contest as had entered in any previous year.', 'Many more of the entries in the contest were from amateurs than were from professionals.', 'Each category in the contest was restricted to amateurs only or professionals only, and there were more categories open to amateurs.']