Refer to the exhibit.

Implementing network summarization on the edge routers is the correct EIGRP design action to reduce query range and improve convergence. In EIGRP, when a route is lost and no feasible successor exists, DUAL sends queries to neighbors. If the network is large or poorly summarized, those queries can propagate widely and increase convergence time. Hierarchical addressing allows each office or edge block to advertise a summary instead of many specific prefixes. If a specific subnet inside an office fails, the summary can remain stable toward the rest of the network, preventing the failure from triggering unnecessary queries across the dark-fiber interoffice topology. Stub routing can also reduce query scope, but the option says to configure stub areas on non-edge routers, which is not the right EIGRP terminology or placement. Different EIGRP processes add redistribution complexity, and route filtering alone does not provide the same clean convergence boundary as summarization. Reference topics: EIGRP summarization, DUAL query scope, hierarchical addressing, convergence optimization, dark-fiber campus routing.