What does an incidental main motion relate to?

An incidental main motion is specifically related to the business of the assembly and its past or future actions. This type of motion is designed to address issues that arise during the discussion of other motions or agenda items. It typically seeks to bring forth new matters that are auxiliary to the main topic being considered but still relevant to the assembly's overarching business.

The emphasis on the assembly's business highlights that these motions aim to facilitate the progression of discussion and decision-making within the context of the established agenda. Incidental main motions can cover a variety of topics, including requests for clarification on past decisions or proposals for future actions that directly impact the assembly's operations.

Other options do not align with the specific nature of an incidental main motion. The prevailing sentiment of the assembly is more general and does not pertain directly to the formalities of motion making. Personal matters of the members are typically not the focus of formal parliamentary procedure unless they impact the assembly's business. The adoption of the previous motion is also more about maintaining continuity in discussions rather than introducing new business. Thus, the focus on the assembly's ongoing and historical business is what makes option B the correct answer.