Answer:
I think because he is popular.
But if I'm wrong may some one correct me.
Question: How does Ms. Chen act as a moderator in this part of the transcript?
Answer: D) She asks the participants to clarify their viewpoints and introduce supporting facts.
"MS. CHEN. Why do you think so, Luisa? What facts support your point of view?"
"MS. CHEN. Does anyone have another opinion?"
"MS. CHEN. Why is that, Raymond?"
All of these sentences help support the fact that she is asking the participants to clarify their viewpoints. This is the best option!