Final answer:
Interior gateway protocols fall under the categories of Distance vector and link state.
Step-by-step explanation:
The two categories that interior gateway protocols fall under are Distance vector and link state. Distance vector protocols like RIP (Routing Information Protocol) use hop count as a metric to determine the best route, whereas link state protocols like OSPF (Open Shortest Path First) use more complex metrics to determine the best path. These protocols are used to route traffic within a single domain, so the correct answer is option B) Distance vector and link state.
In the distance vector category, routers exchange information with their directly connected neighbors, and each router builds a table that holds the best paths to each destination network. Examples of distance vector protocols include Routing Information Protocol (RIP) and Interior Gateway Routing Protocol (IGRP). In contrast, link state protocols require routers to have a complete map of the network topology, which allows them to independently calculate the best path to each destination. Examples of link state protocols include Open Shortest Path First (OSPF) and Intermediate System to Intermediate System (IS-IS).