High availability in Cisco Datacenter Networking is implemented using which two techniques?

High availability in Cisco Datacenter Networking is implemented using which two techniques?

(Choose two)

A.
Extended Spanning Tree Protocol

B.
Virtual Router Redundancy Protocol

C.
Cisco Datacenter Redundancy Protocol

D.
High availability module of the NX-operating system

Explanation:
According to the DCUCD training material, page 5-17:

High availability mechnisms:

Layer 2 mechanisms:
– STP extensions (xSTP)
– UDLD
– RSTP, MST

FHRP:
– HSRP
– VRRP
– GLBP