Correct Answer - Option 2 : Extraneous
Extraneous - meaning irrelevant/ unconnected / unrelated to the requirements of the exam. It is the right answer because a students desire to focus on aceing their tests makes them avoid anything unrelated to their exams.
Related - means connected
Outside - means a place on the exterior
Useful - is something that will help - this is
incorrect to the context because if something is useful
no student would avoid it or ‘close their minds’ so to say.