Even though some schools send students to special courses for language exams, the average scores remain low compared to the students who are not sent to the special courses by their schools.

So teachers concludes that the special courses are a waste of money.

We need to challenge this :

A) Those schools which do not send students to the courses have better knowledge of the exams since they are the only schools which participated in the exams prior to 1995. - Yes, those schools know much about exams and they were the only ones participated in the exams prior to 1995 so no need for them to send the students to special courses.

b) Schools that have sent students to the courses since 1995 have experienced a greater drop in their scores than they had prior to 1995. - Not relevant to the argument.

c) The cost of these courses run by outside teachers has risen dramatically since 1995. - Cost is out of scope.

d) The poor design of courses to prepare students for the language exams is not the only reason for their ineffectiveness. - Another reason is not relevant. This does not challenge the argument at all.

e) Since 1995, the number of students who passed the language exams has risen by twenty percent. - Numbers is totally out of scope to the argument.

Answer A