A.True. ADR is a file system directory structure (e.g., /u01/app/oracle/diag), external to the database.

B.False. ADR also stores diagnostics for non-database components (e.g., ASM, listener).

C.False. It’s file-based, not schema-based.

D.True. ADR logs (e.g., alert logs, trace files) are accessible even if the instance is down.

E.True. DIAGNOSTIC_DEST sets the ADR base directory.