Unless limited by the provisions of a collective bargaining agreement or by other statutory provision, a public employer may:
A. direct the work of, hire, promote, assign, transfer, demote, suspend, discharge or terminate public employees;
B. determine qualifications for employment and the nature and content of personnel examinations;
C. take actions as may be necessary to carry out the mission of the public employer in emergencies; and
D. retain all rights not specifically limited by a collective bargaining agreement or by the Public Employee Bargaining Act.