What is a Cisco Nexus 9300 Series Switch?

A.
An all-in-one SDN solution

B.
A modular switch

C.
A virtual software switch

D.
A fixed top-of-rack switch

Explanation:

Reference:
http://www.cisco.com/c/en/us/products/collateral/switches/nexus-9000-
seriesswitches/datasheet-c78-729405.html(search for modular)