What is characterized as an informal and open gathering of individuals with a common interest?

The correct answer is a mass meeting, which is characterized by being an informal and open gathering of individuals who share a common interest. This type of meeting allows for spontaneous discussion, where participants can share ideas, experiences, and opinions without the constraints typically found in more structured or formal settings. Mass meetings usually facilitate community engagement, grassroots organizing, and the exchange of diverse viewpoints on shared concerns.

In contrast, a formal assembly often has a predefined agenda and strict rules of order, which can limit open dialogue. A board meeting typically involves a small group of appointed members convening to discuss specific organizational matters and tends to follow a more formal structure. Meanwhile, a strategic session focuses on planning and decision-making processes, usually involving key stakeholders and requiring in-depth analysis rather than the open dialogue characteristic of a mass meeting.