The Transport Union in Austin, Texas, Enters into a Contract

The Transport Union in Austin, Texas, enters into a contract with the Metropolitan Transportation Authority. The contract requires the government agency to pay a yearly bonus to union members. A year after signing the contract, the Metropolitan Transportation Authority refuses to pay the annual bonus, which triggers a conflict between the union and the agency. A third party intervenes to resolve the conflict between the two parties. The third party evaluates the arguments of both sides and proposes a solution. Both parties have the right to decline the proposal, but they decide to accept it. In the context of the alternatives to work stoppage, the third party in this scenario is an example of a(n)

A) fact finder.
B) arbitrator.
C) stakeholder.
D) moderator.
E) rights enforcer.