We pick d.root-servers.net, one of the 13 root servers (1), and ask it about williampotterlouveralda.bol.com.br and learn that br is delegated to six name servers (2), so we ask c.dns.br where we learn that bol.com.br is delegated to three name servers, including charles.uol.com.br (3), so we ask that one and get the following answer:
Authoritative answer
AUTHORITATIVE for williampotterlouveralda.bol.com.br.