What kind of public speaking requires minimal preparation time for the speaker?

The correct choice involves impromptu speaking, which is characterized by its spontaneity and lack of extensive preparation. In this type of speaking, the speaker is often given a topic unexpectedly and must formulate their thoughts and present them on the spot. This format tests the speaker's ability to think quickly and communicate effectively without the benefit of having prepared their remarks in advance.

Impromptu speaking is often used in various settings, such as classroom discussions, meetings, or social gatherings, where an immediate response is expected. It relies heavily on the speaker's knowledge of the subject matter, their articulation skills, and their ability to engage the audience without prior planning. This makes it distinct from other forms of speaking, such as prepared or informative speaking, where advance preparation and structure are required.