@mmslf75:
When we weaken an argument we are finding a choice that makes the conclusion less likely to be true (than it was prior to our reading of that answer choice)--you can take this as the definition of weaken. On the GMAT, by far the most common way an answer choice will do this is by attacking the assumption.
Choice D does neither. Choice D tells you that public schools afford more of these opportunities for college. Does this weaken either of the conclusion or assumption? Nope. Even with these opportunities, we still know from stated evidence in the argument that the fraction of students going on to college is way higher with private schools than it is with public schools. Choice D does not change this.
The argument can be viewed as cause-effect. The author thinks the cause of the discrepancy in college-going rates between the two schools is quality of education. Choice E attacks this assumption by suggesting alternative causation for this effect (ie, that it is by choice rather than quality of education that many public school kids don't go on to college).
When we weaken an argument we are finding a choice that makes the conclusion less likely to be true (than it was prior to our reading of that answer choice)--you can take this as the definition of weaken. On the GMAT, by far the most common way an answer choice will do this is by attacking the assumption.
Choice D does neither. Choice D tells you that public schools afford more of these opportunities for college. Does this weaken either of the conclusion or assumption? Nope. Even with these opportunities, we still know from stated evidence in the argument that the fraction of students going on to college is way higher with private schools than it is with public schools. Choice D does not change this.
The argument can be viewed as cause-effect. The author thinks the cause of the discrepancy in college-going rates between the two schools is quality of education. Choice E attacks this assumption by suggesting alternative causation for this effect (ie, that it is by choice rather than quality of education that many public school kids don't go on to college).
Kaplan Teacher in Toronto












