The correct answer is option 4Concept:Dynamic routing, also called adaptive routing, is a process where a router can forward data via a different route or given destination based on the current conditions of the communication circuits within a system:Explanation:There are several protocols that can be used for dynamic routing.Routing Information Protocol (RIP) is a distance-vector routing protocol that prevents routing loops by implementing a limit on the number of hops allowed in a path from source to destination. Open Shortest Path First (OSPF) uses a link-state routing (LSR) algorithm and falls into the group of interior gateway protocols (IGPs).Intermediate System to Intermediate System (IS-IS) determines the best route for data through a packet-switched network.Interior Gateway Routing Protocol (IGRP) and its advanced form Enhanced Interior Gateway Routing Protocol (EIGRP) are used by routers to exchange routing data within an autonomous system.Dynamic routing protocol enables routers:To discover and maintain routesTo distribute routing updates to other routersTo reach agreement with other routers about the network topology