Final answer:
The primary role of a security guard during a labour dispute is to protect people and property, and to provide access control, without getting involved in the negotiation aspects of the dispute.
Step-by-step explanation:
The primary role of a security guard during a labour dispute is to protect people and property from harm or loss, and to provide access control to the property. This is encapsulated in option D from the provided choices. While other roles mentioned, such as helping in the resolution of the dispute or ensuring fair treatment of workers, might be assumed to fall under the scope of the security guard's duties, their fundamental responsibility does not extend to such functions. The objective here is not to interfere with the negotiation processes or involve themselves in the matters that are usually reserved for unions, management, or law enforcement agencies.
Labor unions serve as a collective voice for workers, advocating for better wages, work conditions, and benefits. Negotiations are typically handled through collective bargaining and may involve strikes as a last resort. Security guards during these situations must maintain order and safeguard the premises they are assigned to, remaining neutral to the dispute itself.