What benefit does controller-based networking provide versus traditional networking?

A、movesfromatwo-tiertoathree-tiernetworkarchitecturetoprovidemaximumredundancy
B、providesanaddedlayerofsecuritytoprotectfromDDoSattacks
C、allowsconfigurationandmonitoringofthenetworkfromonecentralizedpoint
D、combinescontrolanddataplanefunctionalityonasingledevicetominimizelatency