A student justifying his bad marks in an examination saying that the teacher did not give him the marks that he deserve because he does not like him, is an example of which defence mechanism:
Projection is a defence mechanism for resolving conflicts where the individual blames others for his failure or mistakes. Here the student projects his mind on to the teacher. Actually he hates the teacher and not the other way round. Ref: Park 21st edition page: 627.
Escape mechanism
Projection
Regression
Displacement