What type of motion must be made when no other business is pending?

The correct answer is that a main motion must be made when no other business is pending. A main motion is the primary way to introduce a topic or a new idea for consideration by a group. In the context of parliamentary procedure, when there are no existing motions or business items on the floor, the group must utilize a main motion to initiate discussion or action on a specific matter.

Understanding the other types of motions can provide clarity on their roles in meetings. Secondary motions are often used to modify or provide additional context to a main motion but cannot be introduced unless there is already a main motion under consideration. Incidental motions arise out of other motions or proceedings and pertain to the current business, while subsidiary motions assist in handling a main motion but cannot stand as the initial proposal for action. By adhering to the structure of parliamentary procedure, the main motion operates effectively as the foundational method for bringing new business before an assembly.