oracle ocp 19c考題，科目082考試題(19)-set unused column

19、choose the best answer Evaluate the following SQL statement:

ALTER TABLE hr.emp

SET UNUSED (mgr_id);

Which statement is true regarding the effect of the above SQL statement?

A) Any views created on the EMP table that include the MGR_ID column would be automatically modified and remain valid.

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

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

D) Any index created on the MGR in column would continue to exist until the DROP UNUSED COLUMNS command is executed.

source : cuug