View the Exhibit and examine the structure of the ORDERS table. 
Which UPDATE statement is valid?
A.
UPDATE orders
SET order_date = 12-mar-2007\ order_total IS NULL WHERE order_id = 2455;
B.
UPDATE orders
SET order_date = 12-mar-2007′, order_total = NULL WHERE order_id = 2455;
C.
UPDATE orders
SET order_date = ’12-mar-2007′
AND order_total = TO_NUMBER(NULL)
WHERE order_id = 2455;
D.
UPDATE orders
SET order_date = TO_DATE(’12-mar-2007,l,dd-mon-yyyy’)l SET order_total =
TO_NUMBER(NULL) WHERE order id = 2455;