What helps to ensure that Switch 2 sends multicasts and broadcasts over both of its switch-to-switch links?

Refer to the exhibit.

The switches shown in the exhibit form a TRILL region. The network administrator has enabled TRILL.

What helps to ensure that Switch 2 sends multicasts and broadcasts over both of its switch-to-switch links?
A . Configure a switch to be the tree root bridge and allow the creation of multiple trees.
B . Configure Switch 3 and Switch 4 with the same designated routing bridge (DRB) priority.
C . Configure Switch 2 with multiple MSTP instances, which are mapped to TRILL access VLANs.
D . Configure Switch 2 to enable TRILL Equal Cost Multi-Path (ECMP) globally.

Answer: D

Explanation:

Equal-cost multi-path routing (ECMP) is a routing strategy where next-hop packet forwarding to a single destination can occur over multiple "best paths" which tie for top place in routing metric calculations.

References: https://en.wikipedia.org/wiki/Equal-cost_multi-path_routing