Passage Summary: The sociologist argues that because success requires trust, and traditional social norms (like white lies) destroy sincerity, people must be honest and face reality for a community to thrive.

Conclusion: For a community to be successful, its members must be willing to confront unpleasant truths and speak about them with honesty.

Reasoning: Traditional norms prevent sincerity by encouraging people to ignore reality and tell small lies, yet a community cannot succeed without trust among its members.

Analysis: This is a Sufficient Assumption question where we need to bridge the gap between 'trust' and 'honesty/facing reality.' The argument establishes that success requires trust and that traditional norms (lying/ignoring reality) prevent sincerity. However, it never explicitly states that trust requires sincerity or honesty. To make the conclusion follow logically, we need an assumption that connects these dots—specifically, that trust is impossible without the members being honest and facing unpleasant realities. Look for an answer that makes sincerity or honesty a requirement for trust.