What type of supporting material did David use by recounting a personal story in his speech about drinking and driving?

David used a personal story in his speech about drinking and driving, which is best categorized as a personal illustration. This kind of supporting material is effective for engaging the audience and providing a relatable example that emphasizes the dangers or consequences of the topic being discussed. A personal illustration draws on the speaker's own experiences to evoke emotion and provide context, making the argument more persuasive.

While an anecdote can also refer to a short personal story, personal illustrations emphasize individual experiences with the intention of exemplifying a broader point, which aligns closely with the use of David's story in this context. This type of supporting material adds depth to the speech by presenting a real-life situation that the audience can connect to, enhancing the overall impact of the message regarding drinking and driving.