1.14 If a PRIMARY KEY constraint named ORDERITEMS_PK exists for the ORDER\# and ITEM\# columns of the ORDERITEMS table, which of the following commands will disable the constraints? a. ALTER TABLE orderitems DISABLE PRIMARY KEY CONSTRAINT b. ALTER TABLE orderitems DISABLE CONSTRAINT oderitems pk c. ALTER TABLE orderitems REMOVE PRIMARY KEY CONSTRAINT d. ALTER TABLE orderitems MODIFY PRIMARY KEY CONSTRAINT DISABLE 1.15 Sequence numbers are primarily used to generate which one of the following values? a. foreign keys b. indexes c. primary keys d. synonyms