The environmental variable ORACLE_BASE is set. You want to check the diagnostic files
created as part of the Automatic Diagnostic Repository (ADR). View the Exhibit and note the
various parameters set in your database.
What will be the location of the ADR base?
Exhibit:
A.
It is set to ORACLE_BASE.
B.
It is set to ORACLE_HOME/log.
C.
It is set to /u01/app/oracle/admin/orcl/adump.
D.
It is set to /u01/app/oracle/flash_recovery_area.
Explanation:
The ADR root directory is known as ADR base. Its location is set by the
DIAGNOSTIC_DEST initialization parameter. If this parameter is omitted or left null, the
database sets DIAGNOSTIC_DEST upon startup as follows:
If environment variable ORACLE_BASE is set, DIAGNOSTIC_DEST is set to the directory
designated by ORACLE_BASE.
If environment variable ORACLE_BASE is not set, DIAGNOSTIC_DEST is set to
ORACLE_HOME/log.
A is correct:
https://docs.oracle.com/cd/B28359_01/server.111/b28310/diag001.htm
Structure, Contents, and Location of the Automatic Diagnostic Repository
The Automatic Diagnostic Repository (ADR) is a directory structure that is stored outside of the database. It is therefore available for problem diagnosis when the database is down.
The ADR root directory is known as ADR base. Its location is set by the DIAGNOSTIC_DEST initialization parameter. If this parameter is omitted or left null, the database sets DIAGNOSTIC_DEST upon startup as follows:
If environment variable ORACLE_BASE is set, DIAGNOSTIC_DEST is set to the directory designated by ORACLE_BASE.
If environment variable ORACLE_BASE is not set, DIAGNOSTIC_DEST is set to ORACLE_HOME/log.