Which two statements are true about the statistics leve…

Your database instance is started using an SPFILE. You are connected to cdb$root, as a DBA. You issue:
SQL> ALTER SYSTEM SET STATISTICS_LEVEL=ALL SCOPE=BOTH;
Which two statements are true about the statistics level parameter?

A.
It is immediately set to all in the SPFILE and the CDB instance.

B.
It is immediately set to all in only those pluggable databases (PDBs) where the value is set to typical.

C.
It is immediately set to all only for cd3Sroot.

D.
It is immediately set to all in all PDBs where the statistics_level parameter is not set.

E.
It is set to all for all PDBs only in the SPFILE.

Explanation: