The correct answer is VLAN tagging. Voice VLAN tagging allows VoIP phones and other compatible devices to automatically be assigned to a separate VLAN dedicated to voice traffic. This practice effectively separates and prioritizes voice traffic from the rest of the data network, which reduces the chance of jitter and latency for voice communications. By using a different VLAN for voice traffic, Quality of Service (QoS) can be more easily applied to ensure that the necessary bandwidth and priority are allocated to voice, which is a real-time application. Port security, while important for network security, doesn't address the need to separate traffic types. Jumbo frames are typically used to improve performance for large data transfers and wouldn't necessarily benefit voice traffic, which consists of small, real-time packets. Duplex settings relate to the transmission direction and capability and do not pertain to traffic segmentation or prioritization.