Given the tables have been created without foreign keys added, which of the following ALTER TABLE statements would create a foreign key on the department$\_$id in the employee table to reference the department$\_$id in the department table?

a$.)$

ALTER TABLE employee

ADD CONSTRAINT fk$\_$employee

FOREIGN KEY $($department$\_$id$)$

REFERENCES department $($department$\_$id$)$;

b$.)$

ALTER TABLE employee

ADD CONSTRAINT

FOREIGN KEY $($department$\_$id$)$

REFERENCES department $($department$\_$id$)$;

c$.)$

ALTER TABLE department

ADD CONSTRAINT fk$\_$employee

FOREIGN KEY $($department$\_$id$)$

REFERENCES employee $($department$\_$id$)$;

d$.)$

ALTER TABLE employee

ADD CONSTRAINT fk$\_$employee

FOREIGN KEY department $($department$\_$id$)$

REFERENCES department$\_$id;