Examine the following statement that is used to modify the constraint on the SALES table： SQL> ALTER TABLE SALES MODIFY CONSTRAINT pk DISABLE VALIDATE； Which three statements are true regarding the above command（）

A.The constraint remains valid.

B.The index on the constraint is dropped.

C.It allows the loading of data into the table using SQL*Loader.

D.New data conforms to the constraint， but existing data is not checked

E.It allows the data manipulation on the table using INSERT/UPDATE/DELETE SQL statements.