Answer:
self-fulfilling prophecy
Explanation:
According to my research on studies conducted by various psychologists, I can say that based on the information provided within the question Sarah's situation is an example of a self-fulfilling prophecy. This term refers to when an individual predicts that something is going to happen, and then subconsciously adjusts their behavior, which in term causes that event to happen. In this situation Sarah believes that she is going to get nervous for her speech, which in term becomes the stressor that causes her to get nervous.
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