Which type of protocol is used to exchange routing information between Wide Area Networks (WANs)?

The correct answer is the type of protocol known as Exterior Gateway Protocols. These protocols are specifically designed for exchanging routing information between different autonomous systems, which are commonly found in Wide Area Networks (WANs). An autonomous system can be thought of as a large network or group of networks that is managed by a single organization and operates under a unified routing policy.

Exterior Gateway Protocols, such as the Border Gateway Protocol (BGP), facilitate communication across varying administrative domains, allowing networks to share information about how to route data effectively across the internet or between different WANs. This is crucial for maintaining efficient connectivity and optimizing data paths between geographically dispersed networks.

In contrast, Interior Gateway Protocols, which are used within a single autonomous system, manage routing within a local area or a specific organization rather than between separate networks. Dynamic Routing Protocols refer to a broader category that can include both interior and exterior protocols, but does not specifically denote the exchange across WANs. Static Routing Protocols are not dynamic at all; they rely on manually configured routes and do not adapt to network changes or exchange information as dynamically as the protocols that update routing tables based on network changes. Thus, Exterior Gateway Protocols are specifically tailored to handle the unique requirements of WAN routing.