After writing an exam, Yani told everybody that he studied really hard and spent a great deal of time preparing for the exam. However, when the exam grades were posted the following week, Yani did not talk about how he studied but instead told everybody that the exam was not fair and was poorly graded. What is this an example of$?$

The fundamental attribution error

Perceptual defence

The actor$-$observer effect

Contrast effects

The self$-$serving bias