Final answer:
The recommended method to confirm ownership of a domain in Office 365 is by adding a DNS TXT record with a specific value.
Step-by-step explanation:
For Office 365 to confirm ownership of a domain, the recommended method is to add a DNS TXT record with a specific value.
To do this, you need to login to the DNS provider for the domain, such as your domain registrar or DNS hosting provider, and navigate to the DNS management section.
From there, you can create a new TXT record with the specific value provided by Office 365. Once the TXT record is added, Office 365 will check the DNS records and confirm ownership of the domain.