Final answer:
A guideline for choosing a speech topic is to select a topic that is appropriate for your audience, to choose a topic that is of interest to you, and to select a topic that has a lot of evidence and specific details available.
Step-by-step explanation:
When choosing a speech topic, it is important to follow certain guidelines. One of the guidelines is to select a topic that is appropriate for your audience (c). This means considering their interests, knowledge, and perspective. Another guideline is to select a topic that is of interest to you (as mentioned in the provided resources) (2). This will help you stay engaged and passionate about the topic, which will come across in your delivery. Lastly, it is also beneficial to choose a topic that has a lot of evidence and specific details available (3) as this will make it easier to develop and support your speech.