"... is a dispute resolution method conducted voluntarily with the participation of an impartial and independent third person who has gone through a special training and who, by applying systematic techniques, is bringing the parties together to discuss and negotiate; ensuring mutual understanding between the parties and the development of a communication process in order for them to produce their own solutions, and who may suggest a resolution in case it becomes apparent that the parties may not find a mutual solution."

With which of the following should the blank in the sentence above be filled?