Which feature is a hallmark of physical trunks?

The hallmark of physical trunks is that they are reliant on specific physical infrastructure. Physical trunks are dedicated connections that use tangible cables (like copper or fiber optics) to establish communication pathways between systems or networks. This reliance on concrete infrastructure is fundamental because the operation of physical trunks depends on the hardware components that provide the necessary bandwidth and connectivity.

In contrast, other choices do not accurately represent the characteristics of physical trunks. While adaptability and scalability are features often associated with modern networking technologies, they are typically more relevant to virtual or cloud-based systems rather than strictly physical configurations. Software management and reconfiguration through software pertain to virtualization or software-defined networking, which are not defining features of physical trunks.