What is the effect of specifying the "ENABLE PLUGGABLE DATABASE" clause in a "CREATE DATABASE” statement?

What is the effect of specifying the “ENABLE PLUGGABLE DATABASE” clause in a “CREATE
DATABASE” statement?

A.
It will create a multitenant container database (CDB) with only the root opened.

B.
It will create a CDB with root opened and seed read only.

C.
It will create a CDB with root and seed opened and one PDB mounted.

D.
It will create a CDB that must be plugged into an existing CDB.

E.
It will create a CDB with root opened and seed mounted.

Explanation:
* The CREATE DATABASE … ENABLE PLUGGABLE DATABASE SQL statement
creates a new CDB. If you do not specify the ENABLE PLUGGABLE DATABASE clause, then the
newly created database is a non-CDB and can never contain PDBs.
Along with the root (CDB$ROOT), Oracle Database automatically creates a seed PDB
(PDB$SEED). The following graphic shows a newly created CDB:

* Creating a PDB
Rather than constructing the data dictionary tables that define an empty PDB from scratch,
and then populating its Obj$ and Dependency$ tables, the empty PDB is created when the CDB
is created. (Here, we use empty to mean containing no customer-created artifacts.) It is referred
to as the seed PDB and has the name PDB$Seed. Every CDB non-negotiably contains a
seed PDB; it is non-negotiably always open in read-only mode. This has no conceptual
significance; rather, it is just an optimization device. The create PDB operation is implemented
as a special case of the clone PDB operation.