What is the location of the Automatic Diagnostic Repository (ADR) home?

Examine the following values of the initialization parameters in the database having the SID ORCL:

BACKGROUND_DUMP_DEST=/u01/app/oracle/product/11.1.0/db_1/bdump
USER_DUMP_DEST=/u01/app/oracle/product/11.1.0/db_1/udump
CORE_DUMP_DEST=/u01/app/oracle/product/11.1.0/db_1/cdump
DIAGNOSTIC_DEST=
The environment variables have the following value:
ORACLE_BASE=/u01/app/oracle
ORACLE_HOME=/u01/app/oracle/product/11.1.0/db_1

What is the location of the Automatic Diagnostic Repository (ADR) home?

A.
/u01/app/oracle/product/11.1.0/db_1

B.
/u01/app/oracle

C.
$ORACLE_HOME/bdump

D.
$ORACLE_HOME/log