​Structure of the PROMOTION Table

Multiple Choice

​Structure of the PROMOTION table

-Which of the following commands will add a UNIQUE constraint to the MINRETAIL column of the PROMOTION table?​

A) ALTER TABLE promotion
ADD CONSTRAINT orderitems_minretail_uk UNIQUE (minretail) ;
B) ALTER TABLE promotion
MODIFY UNIQUE (minretail) ;
C) ALTER TABLE promotion
ADD UNIQUE minretail;
D) ​ALTER TABLE promotion
MODIFY minretail;