In the following conversation, which group discussion technique does Han most clearly show?

EMILY: Han, I got to respectfully disagree with you. History professors wrote both of those books. RAMONA: And history professors are reliable sources?

EMILY: [nodding] Well . . . yeah!

HAN: O.K., normally I would get that. Most history professors would be extra careful about using accurate details to make sure their claims are credible. But I did some extra research.

A. Evaluating an author's point of view

B. Asking clarifying questions

C. Determining new research goals

D. Challenging prevailing ideas

D. Challenging prevailing ideas

The group discussion technique that Han most clearly shows is D. Challenging prevailing ideas. Han challenges the prevailing idea that history professors are reliable sources by stating that he did some extra research.

In the given conversation, Han most clearly shows the group discussion technique of "Evaluating an author's point of view." Han mentions that he did some extra research, indicating that he went beyond simply accepting the claims made by the history professors and critically assessed their perspective. Han's statement suggests that he considered multiple viewpoints and sought additional evidence to support or challenge the claims made by the authors, showing the technique of evaluating an author's point of view.