The correct answer is A because VXLAN/EVPN data-center fabrics are normally built on a routed Layer 3 underlay. In this design, each top-of-rack switch forms independent routed links toward the core or spine layer, and equal-cost multipath routing is used to provide scale-out bandwidth and resilience. The VXLAN/EVPN overlay then provides Layer 2 and Layer 3 tenant connectivity above that routed underlay. Option B is incorrect because LAG member Layer 2 ports represent a traditional Layer 2 aggregation design, not the preferred underlay model for EVPN/VXLAN. Option C is also incorrect because standalone Layer 2 links would create an underlay that lacks the routed ECMP characteristics expected in this fabric architecture. Option D is not the best answer because LAG is not required between TOR and core switches in an EVPN routed fabric; independent routed links provide better fabric behavior and failure isolation. The course includes Aruba networking and advanced virtualization/data-center design topics, and this question tests the candidate’s ability to select the correct port model for an HPE Aruba EVPN/VXLAN solution.