Which type of motion is used to introduce a new subject for discussion?

The main motion is the correct choice for introducing a new subject for discussion because it is the primary way members of a group or assembly formally propose ideas or actions for consideration. This type of motion allows participants to bring forward new business matters, thereby facilitating the effective governance and decision-making process in meetings.

When using a main motion, the presenter clearly states the purpose and proposal, allowing for discussion and debate before a vote is taken. This process is crucial in ensuring that all members have the opportunity to consider and express their opinions on the proposed subject matter.

In contrast, subsidiary motions are primarily used to modify or dispose of a main motion that is currently under consideration. Incidental motions deal with procedural issues arising during a meeting, while privileged motions pertain to urgent matters that require immediate attention and cannot be postponed. Each of these types of motions serves a specific function but does not serve to introduce new topics for discussion like the main motion does.