Rivalry and competition among firms in the same industry will result in: O the same level of monopoly power O less monopoly power O not enough information to answer O more monopoly powerCooperation among firms in the same industry will result in: O less monopoly power O not enough information to answer more monopoly power O the same level of monopoly powerEconomies of scale result in 0 lower per-unit costs at high output levels 0 enhanced technological change 0 higher productivity 0 lower per-unit costs at low output levels A natural monopoly is characterized by: O low variable costs O high fixed costs O low fixed costs O high variable costs