Final answer:
The metric used by a neighboring router that is advertising to this device in EIGRP is the b)Advertised Metric, which represents the cost or distance to reach the destination network.
Step-by-step explanation:
The metric used by a neighboring router that is advertising to this device in EIGRP is called the b)Advertised Metric. The Advertised Metric is a value that represents the cost or distance to reach the destination network. It is used by EIGRP to determine the best path to a network and to calculate the overall EIGRP metric.
For example, if a neighboring router is advertising a network with an Advertised Metric of 20 to our device, it means that the cost or distance to reach that network is 20. This information is used by the receiving device to make routing decisions.