Question: How does an end-station select PTP timing information of interest when receiving (g)PTP messages from multiple domains?
Option 1: Based on the source IP address of the (g)PTP message.
Option 2: Based on the destination MAC address of the (g)PTP message.
Option 3: Based on the VLAN ID of the (g)PTP message.
Option 4: Based on the "domainNumber" in the (g)PTP message.
Explanation: According to the text, an end-station can select PTP timing information of interest based on the "domainNumber" in the (g)PTP message. This allows the end-station to identify and process the timing information from different domains.