The answer is: D
Explanation
The correct option is D: Negotiation.
Negotiation is the process whereby interested parties resolve disputes, agree upon courses of action, bargain for individual or collective advantage, and/or attempt to craft outcomes which serve their mutual interests. This definition is given by the Program on Negotiation at Harvard Law School¹.
Negotiation differs from the other options in the following ways:
Expert determination is a procedure in which a dispute or a difference between the parties is submitted, by agreement of the parties, to one or more experts who make a determination on the matter referred to them. The determination is binding, unless the parties agreed otherwise.
Arbitration is a form of alternative dispute resolution in which the parties to a dispute agree to submit their respective evidence and legal arguments to a neutral third party (the arbitrator or arbitral tribunal) for resolution. The arbitrator's decision is final and binding on the parties, unless they agree otherwise.
Conciliation is a confidential, voluntary and private dispute resolution process in which a neutral person helps the parties to reach a negotiated settlement. The conciliator does not decide for the parties, but assists them in generating options and finding a solution that is compatible for both of them.
Therefore, negotiation is the only option that involves a strategic discussion between the parties to resolve an issue in a way that both find acceptable, without involving a third party decision-maker.