Four fans predicted the situation of several teams before the promotion of a game  They paid more attention to two of them  The four make the following predictions: Fang said that if team A cannot promote, then team B cannot promote  Bai thought that whether team A can promote or not, team B can't promote  Xia held the view that team B can promote, but team A can't  Deng argued that all of these teams cannot promote
The results of the game proved that only one of the four fans was right
If team A cannot promote, then Fang's prediction is correct.