Which action likely requires a motion to be 'seconded'?

Introducing a new topic typically requires a motion to be 'seconded' because it is essential to ensure that more than one member of the assembly supports the consideration of that topic before it is discussed. This process helps to establish that there is sufficient interest in the matter before the group expends time and resources on it. A second shows that at least one other person believes the topic is worth discussing, thereby legitimizing it for the assembly as a whole.

In contrast, declaring a meeting adjourned is often a matter that can be done without a formal second, as it is usually an accepted practice and can be made by the presiding officer. Changing the order of business is typically a procedural action that may not require seconding if it is stipulated by the rules being followed, as it can fall under the chair's authority or established protocols. Voting on a pre-existing proposal is a straightforward action where a second is not needed because the group has already expressed interest in the proposal through the initial motion, which has already been seconded and discussed.