If some students fail in the examination it is the fault of

option 3 : seems correct

The teacher,cause children can not be wrong and we can't blame them it is the system which has failed

It's and is the teacher coz if a child fails system or teacher is also fails

There should be one more option instead of text book i.e, All of the above, But in the competitive exam's books answer is considering option 3 which is pupils themselves

There should be one more option i.e, All of the above instead of option 4 ,Although in many competitive books answer is considered option 3 which pupils themselves