Which characteristic is associated with being "diffident"?

The term "diffident" describes someone who is modest or shy, often characterized by a lack of self-confidence or a reserved demeanor in social situations. This characteristic is directly tied to the idea of showing modest reserve, as a diffident person tends to be more introspective and cautious about expressing their opinions or asserting themselves in public.

Given this definition, the choice that aligns with being "diffident" is showcasing modest reserve. A diffident individual may avoid drawing attention to themselves or boasting about their achievements, exhibiting a quiet uncertainty instead. This behavior reflects a thoughtful and restrained approach to social interactions, contrasting sharply with traits of overconfidence or self-promotion.

In essence, the accuracy of the correct answer derives from recognizing that diffidence is fundamentally about a lack of boldness and an inclination toward humility, rather than any assertiveness or leadership qualities.