Which component of the Toulmin Model of Argument is indicated by words in a claim such as "likely," "possibly," or "probably"?

Keith has just finished his speech, and he is responding to questions. One listener

poses a question that baffles Keith. What should he do? A) Rephrase the question as something he can respond to adequately and answer that. B) Admit that he doesn't know, but say that he will look into it and get in touch with the listener. C) Give an ambiguous answer in order to maintain his credibility and control of the setting. D) Ask if anyone else knows the answer and direct everyone's attention their way.

Quoting or paraphrasing words and phrases without identifying the source is known as

a. providing false information b. advocating harm c. plagiarizing d. card-stacking