In crafting her speech about carbon monoxide detectors, Janet used which type of proposition for her central idea?

The central idea of a speech about carbon monoxide detectors would most appropriately align with a proposition of policy. This is because such a speech is likely advocating for a specific course of action, such as the installation of carbon monoxide detectors in homes or promoting legislation related to their use. Propositions of policy focus on what should be done or what actions ought to be taken, which fits the context of urging the audience to implement safety measures regarding carbon monoxide.

In contrast, a proposition of value would evaluate the worth or morality of an idea or concept. A proposition of fact would present information that can be proven true or false, such as data on the dangers of carbon monoxide. A proposition of opinion would express a personal belief or perspective without necessarily advocating for action. Therefore, the nature of Janet's central idea clearly aligns with advocating for a particular policy related to the use of carbon monoxide detectors.