Speakers who explain their expertise on the speech topic are likely to reduce their credibilty with the audience

Persuasion is an umbrella term of influence. Persuasion can attempt to influence a person's beliefs, attitudes, intentions, motivations, orbehaviors.[1] In business, persuasion is a process aimed at changing a person's (or a group's) attitude or behavior toward some event, idea, object, or other person(s), by using written or spoken words to convey information, feelings, or reasoning, or a combination thereof.[2]Persuasion is also an often used tool in the pursuit of personal gain, such as election campaigning, giving a sales pitch,[3] or in trial advocacy. Persuasion can also be interpreted as using one's personal or positional resources to change people's behaviors or attitudes. Systematic persuasion is the process through which attitudes or beliefs are leveraged by appeals to logic and reason. Heuristic persuasion on the other hand is the process through which attitudes or beliefs are leveraged by appeals to habit or emotion.[4]

In a group discussion,which of these is the best example of challenging credibility of a source. the answer choice is a