Evaluate the following statements：   CREATE TABLE purchase_orders （po_id NUMBER（4），  po_date TIMESTAMP， supplier_id NUMBER（6）， po_total NUMBER（8，2），  CONSTRAINT order_pk PRIMARY KEY（po_id）） PARTITION BY RANGE（po_date）  （PARTITION Q1 VALUES LESS THAN （TO_DATE（？1-apr-2007？d-mon-yyyy？）， PARTITION Q2 VALUES LESS THAN  （TO_DATE（？1-jul-2007？d-mon-yyyy？），  PARTITION Q3 VALUES LESS THAN（TO_DATE（？1-oct - 2007？d-mon-yyyy？）， PARTITION Q4 VALUES LESS THAN （TO_DATE（？1-jan-2008？d-mon-yyyy？））；  CREATE TABLE purchase_order_items （po_id NUMBER（4） NOT NULL， product_id NUMBER（6） NOT NULL， unit_price NUMBER（8，2）， quantity NUMBER（8）， CONSTRAINT po_items_fk FOREIGN KEY  （po_id） REFERENCES purchase_orders（po_id）） PARTITION BY REFERENCE（po_items_fk）；   What are the two consequences of the above statements？（）

• A、 Partitions of PURCHASE_ORDER_ITEMS have system-generated names.
• B、 Both PURCHASE_ORDERS and PURCHASE_ORDER_ITEMS tables are created with four partitions each. 
• C、 Partitions of the PURCHASE_ORDER_ITEMS table exist in the same tablespaces as the partitions of the PURCHASE_ORDERS table.
• D、 The PURCHASE_ORDER_ITEMS table inherits the partitioning key from the parent table by  automatically duplicating the key columns.
• E、 Partition maintenance operations performed on the PURCHASE_ORDER_ITEMS table are automatically reflected in the PURCHASE_ORDERS table.