Given the following (normalized) relational model (primary keys underlined; foreign keys in italics): EMPLOYEE(SSN, ENAME, EADDRESS, SEX, DATE_OF_BIRTH, SUPERVISOR, DNR) SUPERVISOR: foreign key, refers to SSN in EMPLOYEE, NULL value not allowed DNR: foreign key, refers to DNR in DEPARTMENT, NULL value not allowed DEPARTMENT(DNR, DNAME, DLOCATION, MGNR) MGNR: foreign key, refers to SSN in EMPLOYEE, NULL value not allowed PROJECT(PNR, PNAME, PDURATION, DNR) DNR: foreign key, refers to DNR in DEPARTMENT, NULL value not allowed WORKS_ON(SSN, PNR, HOURS) SSN: foreign key, refers to SSN in EMPLOYEE, NULL value not allowed PNR: foreign key, refers to PNR in PROJECT, NULL value not allowed Which statement is NOT CORRECT? According to the model, an employee can work in another department than he/she manages. Every employee must be always supervised by exactly one other employee. A department has always exactly one manager. Every project is always assigned to exactly one department