Answer:
Overgeneralization
Step-by-step explanation:
In psychology, Overgeneralization is a term used to describe an issue that affects mostly mentally ill people with anxiety or depressive disorders on a regular basis. It occurs when someone thinks and applies only one experience and generalize it to all other experiences, including those yet to occur. In this case, just for once that her professor did not say hello back to her, she is already thinking of the future (if she would pass the class) and if her professor was angry at her.