Which of the following tactics is used only by management?

Lockouts are a tactic employed exclusively by management during labor disputes. In a lockout, the employer prevents workers from entering the workplace in order to urge them to accept certain terms or conditions during negotiations. This action is typically taken when a labor contract is about to expire or if a dispute arises over wages, working conditions, or other employment terms.

Management utilizes lockouts as a strategic move to exert pressure on employees or unions, effectively halting production and indicating the seriousness of their position. This contrasts with tactics like picketing or boycotting, which are actions taken by workers or labor unions as forms of protest against management's decisions or policies. Negotiation, while vital to both management and workers, is a collaborative process aimed at reaching agreements, rather than an adversarial tactic. Thus, the correct answer highlights a specific strategy that belongs to management in labor relations.