What was the final stage that tuckman added to his enhanced group development model?

The last time he flew jet value air, juan's plane developed a fuel leak and had to make an 4) emergency landing. the time before that, his plane was grounded because of an electrical problem. juan is sure his current trip will be fraught with problems and he will once again be delayed. this is an example of the bias a) confirmation b) availability c) selective perception d) randomness