What is the location of the ADR base?

The environmental variable oracle_Base is set to /u01/app/oracle and oracle_home is set to /u01/app/oracle/ product/12.1.0/db 1.
You want to check the diagnostic files created as part of the Automatic Diagnostic Repository (ADR). Examine the initialization parameters set in your database.
NAMETYPEVALUE
—————- ——————- ——————-
audit_file_deststring/u01/app/oracle/admin/eml2rep/adump
background_dump_deststring
core_dump_deststring
db_create_file_deststring
db_recovery_file_deststring/u01/app/oracle/fast_recovery_area
diagnostic_deststring
What is the location of the ADR base?

A.
It is set to/u01/app/oracle/product:/12.1.0/db_1/log.

B.
It is set to /u01/app/oracle/admin/enl2r&p/adump.

C.
It is set to /u01/app/oracle.

D.
It is set to /u01/app/oracle/flash_recovery_area.

Explanation:

http://docs.oracle.com/cd/B28359_01/server.111/b28310/diag001.htm#ADMIN11008
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.