Final answer:
An intermediary, or mediator, is a third party who can assist in negotiating an end to a conflict by facilitating communication and helping the conflicting parties reach a resolution. Therefore, the correct option is A.
Step-by-step explanation:
An intermediary, also known as a mediator, is a third party who can assist in negotiating an end to a conflict. They do not hold a leadership role or take control during a conflict. Rather, they facilitate communication and help the conflicting parties find common ground and reach a resolution. An intermediary does not give advice, but rather acts as a neutral party to guide the negotiation process.