In the context of resolving bargaining deadlocks between two parties, which of the following is a difference between mediation and arbitration?

a$.$ Unlike mediation, arbitration is a voluntary process that relies on the communication and persuasive skills of an arbitrator to help the parties resolve their differences.

b$.$ Unlike a mediator, an arbitrator assumes the role of a decision maker and determines what the settlement between the two parties should be$.$

c$.$ Unlike mediation, arbitration is often used to settle private sector bargaining disputes.

d$.$ Unlike a mediator, an arbitrator has no power or authority to force either side toward an agreement.