Dr$.$ Qiang, a professor at a local university, has been working with union leaders and management at Fairlawn Corporation to help the two sides resolve differences over desired wage levels for a new contract. First, he met with each side privately to determine any common ground for agreement. For the past week, he has worked with representatives from each side to promote communication and compromise at the bargaining table. Dr$.$ Qiang is a$($n$)$

Select one:

a$.$ arbitrator.

b$.$ mediator.

c$.$ fact finder.

d$.$ shop steward.