Passage Summary: Just like people look back on their lives as they get older, people living at the end of a century probably do the same thing with the history of that era.

Conclusion: People at the end of a century will likely spend a significant amount of time reflecting on the events of that hundred-year period.

Reasoning: The author establishes an analogy between a century and a human life, noting that behaviors at the end of a life, specifically reflection, should be mirrored at the end of a century.

Analysis: This argument relies on a direct analogy between a human lifespan and a chronological century. To complete the thought, we need to extend the specific behavior mentioned—looking back on the past—to the century context. Look for an answer that mirrors the 'looking back' behavior specifically for the hundred-year period. It's a classic LSAT move to use a comparison to predict a specific outcome.