The correct answer is D. To those who oppose my viewpoint, I say that computers will have a bigger effect on student learning.
Step-by-step explanation:
A counterclaim is an argument or position that rebuts another argument, in this case, Karen is trying to show upgrading the equipment in the school computer lab is the best way to spend the budget surplus even though the opposition claims this money should be spent in textbooks. In this way, the counter-argument should help Karen to support her position regarding the budget surplus and rebut the position of other people, due to this "To those who oppose my viewpoint, I say that computers will have a bigger effect on student learning" is the best counterargument because it shows students will be more benefit from Karen's idea that from other people idea, also, it shows the opposition might have considered textbooks support student learning, but are not considering new equipment will probably have the same effect or even a bigger effect, also, this counterclaim implies Karen knows different perspectives and possible effects and as a result she is supporting the position that will benefit the most to the students.