Acme Corporation indicates that their network design must support the ability to scale to support a high number of remote sites. Which IGP is considered to scale better for a hub-and-spoke topology?

BGP is an Exterior Gateway Protocol used for inter-AS routing, not an Interior Gateway Protocol, so it does not satisfy the IGP requirement.

OSPF requires full adjacency formation and LSA flooding across all sites, which creates scalability problems in hub-and-spoke designs due to NBMA complexity and increased overhead as spoke count grows.

IS-IS lacks the stub routing and query-scoping mechanisms that EIGRP provides, making it less optimal for hub-and-spoke environments despite its scalability in large ISP backbones.

EIGRP stub routing allows spoke routers to advertise only connected and summary routes back to the hub, preventing the propagation of EIGRP queries across the WAN and significantly reducing bandwidth and CPU consumption at scale - making it the preferred IGP for large hub-and-spoke designs.