An administrator is building a Lightning app and sees a message that a My Domain must be set up first. What should the administrator take into consideration when enabling My Domain?

A. Single sign-on must be disabled prior to implementing My Domain.

B. The login for all internal and external users changes to the My Domain login

C. A deployed My Domain is irreversible and renaming is unavailable.

D. The URL instance for a My Domain stays the same for every release.