Cisco Exam 300-420 Topic 1 Question 89 Discussion

An engineer is designing a campus network with Cisco Catalyst 95CO switches in the aggression layer. The design requires running nonblocking Layer 2 MEC from the aggregation layer to the access layer. The Catalyst switches are located on different campus floors for availability reasons, and each access switch veil contam a single VLAN. Which technology must the engineer choose for the aggregation switches in the design?