Astudent who is failing but does not study because she refuses to believe that the instructor will really give her an "f" at the end of the term is using the defense mechanism of

The answer is the defense mechanism of denial.

Explanation:

Denial defense mechanism refers to the fact of refusing to accept some aspects concerning reality. Thus, when there is a situation that a person cannot handle, this person decides to deny that the situation exists or the person can reject it. This mechanism is usually used by people to distort reality and in this way avoid anxiety or any undesired impulses.

Moreover, this mechanism is considered one of the first defense mechanisms because it is usually utilized in childhood development.  

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