Under Which Circumstance(s), Can the Public/Visible Network Share the WAN

Multiple Choice

Under which circumstance(s) , can the Public/Visible network share the WAN with the Private network in the Cisco UCCE Clustering over the WAN deployments?

A) SONET WAN with multiple edge devices per Data Center to connect to the SONET ring
B) under no circumstances
C) MPLS WAN with a single edge device per Data Center that connects to multiple 1 Gbps WAN circuits and the failover between the WAN circuits is less than 500 ms.
D) MPLS WAN with multiple 1 Gbps WAN circuits and a fast 100 ms Round Trip latency between Data Centers