You are the Cisco Network Designer in Cisco.com. Which statement is correct regarding NBAR and NetFlow?()
A、NBAR examines data in Layers 1 and 4.
B、NBAR examines data in Layers 3 and 4.
C、NetFlow examines data in Layers 3 and 4.
D、NBAR examines data in Layers 2 through 4.