Here is how I tried solving it.
Conclusion of the argument - It must be, then, that for-profit colleges enroll a greater proportion of financially disadvantaged students than do non-profit colleges.
The conclusion is made based on facts provided between For-profit colleges and Non-profit colleges. Following are the facts that were provided.
1) For-profit colleges have fewer students then Non-profit colleges.
2) For-profit colleges receive more money in the form of federal and state financial aid.
Based on the above facts the argument is concluded as “For-profit colleges enroll more students who are financially weak than non-profit colleges do.
For assumptions questions, one trick is the answer should tie together the facts stated and the conclusion.
Fewer students, more aid --> more students who are financially week.
Now look at the ans choices.
1. The argument is comparing the For-Profit and Non-profit colleges. Not the public and private colleges. Rule this option out.
2. This is in some way tying all the pieces in the argument (atleast you are seeing all the critical words – aid, students…..possible ans.
3. This is also in some way tying all the pieces of the argument (key words being students, aid.). But the problem with this choice is that it is restating the conclusion. Students from for-profit colleges who are receiving aid is greater than students from non-profit colleges. So rule out this option also.
An assumption cannot restate the conclusion. 4. Educational quality is of no relevance with the conclusion. Rule out this option.
5. Students defaulting their loans after the completion of the college is not relevant to the conclusion. Rule out this option.
So my ans will be B.