Identify two correct statements about multitenant architectures.（）

AMultitenant architecture can be deployed only in a Real Application Clusters (RAC) configuration.

BMultiple pluggable databases (PDBs) share certain multitenant container database (CDB) resources.

CMultiple CDBs share certain PDB resources.

DMultiple non-RAC CDB instances can mount the same PDB as long as they are on the same server.

EPatches are always applied at the CDB level.

FA PDB can have a private undo tablespace.