A router running ISIS is showing high CPU and bandwidth utilization. An engineer discovers that the router is configured as L1/L2 and has L1 and L2 neighbors.
Which step optimizes the design to address the issue?
A. Make this router a DIS for each of the interfaces
B. Disable the default behavior of advertising the default route on the L1/L2 router
C. Configure the router to be either L1 or L2
D. Configure each interface as either L1 or L2 circuit type