Answer:Derived credibility
Explanation:
Credibility refers to how one is trustworthy which may make people pay attention to what they say otherwise without being trustworthy audience is less likely to believe what you say.
Derived credibility is the credibility that one is able to create as they speak to the audience or during the speech delivery this is created by the quality and professionalism of one's speech.
So as the word derived mean to get something from , you also get credibility from your speech that you are delivering well if audience sees quality and professionalism in it.