This is a point of disagreement/ point at issue question. These types of question test your ability to spot the difference of opinion between the two speakers either with regard to one of the conclusions or one of the minor details.
One approach is to identify the structure of each speaker's argument and note main points:
R: Great art can only be produced only when artists struggle to express themselves within externally imposed boundaries. Contemporary artists are constraint-free. _______________________________ Quality of art has declined.
J: People are always critical of the art of their time. People forget all but the greatest art from the past. Inferior contemporary art has not yet been forgotten. _________________________________________________ People mistakenly think that contemporary art is of inferior quality.
Do we see any common themes in these arguments?
The speakers clearly reach two opposite conclusions - "quality of art has declined" vs "people mistakingly think ..art is of inferior quality." Their main disagreement is about the quality of contemporary art, thus (A) is the correct answer choice.
Notice that the rest of the answer choices only summarize a point made by one of the speakers, e,g, (B), (C) relate only to R's argument, and (D) to J's, or is outside the scope of the argument entirely (E).
Does this help? Let me know if you have any further questions.
