Behavior that occurs in response to a common influence or stimulus in relatively spontaneous, unstructured or unstable situations

• A. Crowd
• B. Collective behavior
• C. Mass panic
• D. Social norms

Answer: (B)

Collective behavior is about spontaneous, unplanned actions that arise when a large number of people respond to a common influence or stimulus in situations that are unclear, unstable, or lacking formal organization. The description fits this because it emphasizes a shared trigger leading to coordinated behavior without established rules or leadership, often in short-lived, fluid circumstances. For example, a sudden burst of excitement or a rumor can prompt people to act together in ways that aren’t governed by existing social norms or institutions.

This is different from a crowd, which is simply a large gathering of people in one place; the term focuses on the pattern of behavior rather than the physical group. Mass panic would specifically involve fear-driven, irrational behavior, which isn’t necessarily implied here. Social norms are established expectations that guide behavior in a stable society, not the spontaneous responses to a fleeting stimulus described in the prompt.