Although I managed to correctly select D for this problem, I did so with hardly any confidence. Basically I worked my way through the problem purely by eliminating wrong answers, and then selected D based on a "gut" feeling (it looked[i] the least wrong)[/i]. Here was my thinking process for the wrong answers...
First of all, we're looking for an claim that Marc and Robert would both agree with, as supported by their dialogue with one another.
A) There's no real evidence that their country currently faces troubling times, nor do I see any support for the country underrating past problems. Having nostalgia might even prove that they don't underrate past problems.
B) I'm not given indication that the people are looking back in search of present-day solutions, so I eliminate this one quickly.
C) While Marc might agree that the country made mistakes in the past ("regret the recent revolution"), neither speaker gives me an indication that looking to the past for solutions will lead to the same old mistakes.
E) Robert might agree with this, as he thinks the people are nostalgic for the distant past rather than the recent past. I don't know, however, whether Marc would agree with the claim in E.
I broke D down into two parts and tried to find evidence from both Marc and Robert that supported each part:
"Are concerned with the country's current situation..."
Marc: "...they regret the recent revolution."
Robert: "this indicates that although they are troubled..."
"This is evidenced by their nostalgia"
Marc: "The fact that the people of our country look back on the past with a great deal of nostalgia..."
Robert: "They are not nostalgic for the recent past, but for the distant past..."
I would love to hear about a more efficient approach to solving this problem. Thanks in advance!