Which statement about the view created from the following SQL statement is correct? CREATE VIEW ...

Which statement about the view created from the following SQL statement is correct? CREATE VIEW balancedue AS SELECT customer, order, SUM(quantityretail) amtdue FROM customers NATURAL JOIN orders NATURAL JOIN orderitems NATURAL JOIN books GROUP BY customer, order;
 a. No DML operations can be performed through the view.
  b. DML operations can only be performed on the CUSTOMERS table since it is the primary key for the view.
   c. Only rows can be added through the view  no other DML operations are allowed.
  d. none of the above