Which two statements are true about the effect of the above command?

Examine the command that is used to create a table:
SQL> CREATE TABLE orders (
oid NUMBER(6) PRIMARY KEY,
odate DATE,
ccode NUMBER (6),
oamt NUMBER(10,2)
) TABLESPACE users;
Which two statements are true about the effect of the above command? (Choose two.)

A.
A CHECK constraint is created on the OID column.

B.
A NOT NULL constraint is created on the OID column.

C.
The ORDERS table is the only object created in the USERS tablespace.

D.
The ORDERS table and a unique index are created in the USERS tablespace.

E.
The ORDERS table is created in the USERS tablespace and a unique index is created on the OID column in the SYSTEM tablespace.