Which of the following describes a main motion?

A main motion serves as the primary means for introducing new subjects for discussion and decision-making within a meeting. It allows members of the assembly to propose a specific action or initiate a discussion on a particular issue. This fundamental aspect of parliamentary procedure reinforces the participatory nature of meetings, enabling members to contribute to the agenda effectively.

The other choices do not accurately describe the function of a main motion. While some motions require immediate attention or a written submission, these features are not inherent to main motions. Additionally, main motions are typically open for debate during the same meeting they are introduced, making the statement about debating them in the next meeting incorrect. Thus, the description of a main motion as the primary way to bring new topics to the assembly highlights its essential role in facilitating organized discussions and decisions.