Which of the Following Is Correct

Which of the following is correct:

A) Unless the collective agreement provides otherwise, employers can assign work normally done by employees in the bargaining unit to employees outside of the bargaining unit.
B) Employers can assign work normally done by employees in the bargaining unit to the firm's employees outside of the bargaining unit unless the collective agreement restricts contracting out.
C) Supervisors cannot do work normally done by employees in the bargaining unit.
D) Employers can assign work normally done by employees in the bargaining unit to employees outside of the bargaining unit provided that this does not cause layoffs.
E) A collective agreement cannot impose any restrictions on bargaining unit work.