Proof of refusal

Hey! I got accepted in Health Science, and I am definitely going there, but had a couple of questions on how to prove I refused the other schools.

In the email, it said to MIO, but I didn't know who, until I found an admission profile, that's the one right? I haven't gotten an answer yet.

Also, I got waitlisted at Dawson, so do I need to message them to get off that list and then send it to Vanier? Or do nothing?

Thank you smm!