How does NSX simplify the underlying physical network?

[answerhappygod]

How does NSX simplify the underlying physical network?

A. All configuration and state information is available via the REST APIs to automate the configuration of the physical network.
B. All configuration and state information are readily accessible, as is the mapping between virtual network topologies and the physical network.
C. All configuration and state information is stored in the local NSX BPDU database, eliminating the need for Spanning Tree Protocol (STP) on the physical network.
D. All configuration and state information is cached by the NSX controllers, reducing the number of MAC/ARP table entries on the physical network.