The exhibit shows a network topology where Switch-1 and Switch-2 are part of a Virtual Switching Extension (VSX) fabric, and the router runs OSPF on LAG 100, which is a Layer 3 LAG. The question asks how to control how core-to-access traffic is forwarded, which means how the router chooses between the two links to Switch-1 and Switch-2. To force the router to use both links, ensuring that active gateway is enabled on LAG 100 on both Switch-1 and Switch-2 is not the correct solution. Active gateway is a feature that allows both VSX members to act as the default gateway for downstream devices, using a common virtual MAC address. Active gateway does not affect how upstream devices, such as the router, forward traffic to the VSX members1. To force the router to use both links, the correct solution is to configure equal-cost multi-path (ECMP) in OSPF on the router. ECMP is a feature that allows a router to load balance traffic across multiple paths with the same cost. ECMP can be configured using the maximum-paths command and specifying how many equal-cost paths the router should use2. Therefore, this does not correctly explain how to control how core-to-access traffic is forwarded.