A speaker who provides a four-sentence example about Rick Swenson, the five-time winner of the Iditarod Dog Race, is using which of the following?

The correct choice is that the speaker is using an extended, actual example. This is because the speaker provides a detailed narrative about Rick Swenson, including specific information such as his achievements in the Iditarod Dog Race. An extended example typically offers more context and elaboration than a brief example, allowing the audience to better understand and relate to the subject being discussed.

In this case, by citing a real individual and elaborating on his experiences, the speaker enhances the credibility of the information and makes the point more engaging for the audience. This contrasts with brief examples, which would only give minimal information and not fully develop the context. Hypothetical examples would also rely on imagined scenarios rather than real-life cases, thus reinforcing that the speaker is indeed using an actual example in an extended format.