Evalute the follwing SQL statements? ALTER TABLE HR.EMP SET UNUSED ( MGR_ID ); which statements is true ?

Any constraints defined on the MGR_ID column would be removed by the above command

Any views created on the EMP table that include the MGR_ID column would have to bve dropped and re-created

Any index created on the MGR_ID column would continue to exists until the DROP UNUSED COLUMNS command is executed.

Any synonym existing on the EMP table would have to be re-created