Final answer:
Telling a joke is the riskiest strategy to start a speech if you're unfamiliar with your audience due to the subjective nature of humor. Other strategies like anecdotes, rhetorical questions, startling statistics, or relevant quotations can safely captivate the audience and introduce the speech topic effectively.
Step-by-step explanation:
Among the choices given, telling a joke (tell a joke) is the riskiest attention-getting strategy to start a speech, particularly when you are not familiar with your audience. Humor is highly subjective and can be influenced by cultural, personal, and contextual factors. A joke that might be funny in one context can be offensive or confusing in another, which poses a significant risk of alienating the audience at the very beginning of the speech. On the contrary, engaging strategies such as telling an anecdote, asking a rhetorical question (ask a rhetorical question), or presenting a startling statistic are typically safer and can effectively draw readers in. Using a relevant quotation or an interesting fact (interesting fact) can also serve as an intriguing hook that not only garners attention but introduces the topic and paves the way to a strong thesis statement, thus making the introduction valuable to the argument. However, when using a hook, it is crucial to ensure that it's connected to the main topic, as an unrelated hook can detract from the purpose of the introduction.