In ancient times, four long-term workers speculated on the wealth of a rich man  A said that his money would not exceed 250000 Guan  B said that his money would not exceed 300000 Guan  C said that his money was definitely more than 400000 Guan  D said that his money must not be 500000 Guan
A is right
 In fact, only one long-term worker was right