Which three statements are true concerning the multitenant architecture? (Choose three.)

Each pluggable database (PDB) has its own set of background processes. 

A PDB can have a private temp tablespace. 

PDBs can share the sysaux tablespace. 

Log switches occur only at the multitenant container database (CDB) level. 

Different PDBs can have different default block sizes. 

PDBs share a common system tablespace. 

Instance recovery is always performed at the CDB level.