Add the appropriate foreign key$($s$)$ to the Treatment$\_$Appt table. Select the correct SQL$.$

a$.$ ALTER TABLE Treatment$\_$Appt

ADD FOREIGN KEY $($APPOINTMENT$\_$ID$)$ REFERENCES Appointments $($APPOINTMENT$\_$ID$)$;

b$.$ ALTER TABLE Treatment$\_$Appt

ADD FOREIGN KEY $($APPOINTMENT$\_$ID$)$ REFERENCES Appointments $($APPOINTMENT$\_$ID$)$;

ALTER TABLE Treatment$\_$Appt

ADD FOREIGN KEY $($TREATMENT$\_$ID$)$ REFERENCES Treatment $($TREATMENT$\_$ID$)$;

c$.$ ALTER TABLE Treatment$\_$Appt

ADD FOREIGN KEY $($TREATMENT$\_$ID$)$ REFERENCES Treatment $($TREATMENT$\_$ID$)$;