Answer fast.

in "the swan," the sense that the speaker is addressing a large audience creates a(n) tone.

formal
intimate
professional
serious

Formal

Explanation:

We should use a formal tone when we are talking to people at higher levels, older people, people we do not have intimacy with and a large audience. The formal tone gives credibility, authority, knowledge and shows your respect to the person listening to you. In "The Swan", the feeling that the speaker is addressing a large audience creates a formal tone, because the speaker is addressing a large crowd so it would be a sign of respect and warmth to use formal language.