Which DELETE statement would execute successfully?

View the Exhibit and examine the structure of ORDERS and ORDER_ITEMS tables.
ORDER_ID is the primary key in the ORDERS table. It is also the foreign key in the
ORDER_ITEMS table wherein it is created with the ON DELETE CASCADE option.
Which DELETE statement would execute successfully?

A.
DELETE order_id FROM orders
WHERE order_total < 1000;

B.
DELETE orders WHERE order_total < 1000;

C.
DELETE FROM orders
WHERE (SELECT order_id
FROM order_items);

D.
DELETE orders o, order_items i
WHERE o.order id = i.order id;