Answer:
Period (.)
Step-by-step explanation:
A fully qualified domain name (FQDN) is the complete or full domain name for a particular computer, or host, on the internet. As an example, let's say that the FQDN for mail server is mymail.thisschool.edu . We have the hostname to be mymail, now the host is found within the domain thisschool.edu .
In summary a fully qualified domain name contains a hostname and a domain name and it is followed by a period(.)