The correct answer is the following: option A. "The importance of capping college tuition costs" is a topic narrow enough to serve as the subject of a persuasive speech. The main objective of any persuasive speech is for the presenter to convince the audience of adopting his/her viewpoint on a specific subject. This is why the topic of any persuasive speech needs to be somewhat controversial, so that a debate can be started during the speech as well a specific position within that debate. A topic such as "the importance of capping college tuition costs" is already giving the audience an idea of the position that the presenter is taking on the topic, and it is also a narrow theme, is not to broad that cannot be summarized in one direct speech.