Sullivan is losing his patience with Josh. Josh leaves old food and workout clothes in their shared locker. Josh says he is keeping his stuff in his half of the locker, so there should not be an issue. The argument goes on for a month, getting more heated, even resulting in a shouting match in the hall.

Which type of conflict resolution will best help Sullivan and Josh solve the conflict?

Sullivan should use polite refusal skills.
They should seek help from a mediator.
They should avoid contact with each other.
Sullivan should throw away dirty items.