Which of these formats represents the correct hierarchy for the ADR?

Which of these formats represents the correct hierarchy for the ADR?

A.
<diagnostic_dest>/rdbms/diag/<dbname>/<instname>

B.
<diagnostic_dest>/diag/rdbms/<instname>/<dbname>

C.
<diagnostic_dest>/diag/rdbms/<dbname>/<instname>

D.
None of the above