B, C, D: Hi,
A: I am about to say something crazy is that OK?
B, C, D: ....(wondering about the unknown)
A: I promise that you will survive during the whole course when I am saying it. So Can I say it now?
B, C, D: ....(still wondering about the unknown)
A: Here is the document that I have signed so that I will be fully responsible for the consequences of what I am about to say. You will get compensations if any damaging events happen to you during when I am saying it.
So, Can I say it now?
B, C, D: Go ahead!
After a few sentences, A, B, C, D all disappeared.