Final answer:
The quote that encapsulates the idea of the American Dream as an opportunity attainable through hard work and perseverance, and reflects the real-world challenges, is about opportunity and success related to education and employment.
Step-by-step explanation:
The quote that best supports the understanding of the concept of the American Dream in the context of the given question is: "The American Dream has always been based on opportunity...if you study hard, develop good work habits, and graduate high school or, even better, college, then you'll have the opportunity to land a good job." This quote encapsulates the central idea that the American Dream is rooted in opportunity, hard work, and the ability to succeed through personal effort. It relates directly to the idea of the American Dream as a reachable goal, which also implies the difficulties faced during the recession, reflecting the real-world challenges in achieving this dream.