How many Oracle Clusterware interconnect networks are required and why?

How many Oracle Clusterware interconnect networks are required and why?

A.
Only one; minimum requirement

B.
Two; redundancy is required

C.
One per node in the cluster

D.
One per database in the cluster

Explanation:
Oracle Clusterware requires a cluster interconnect configured for inter-node
communication.
Note:
* The Oracle Clusterware interconnect is a non-traditional interconnect and should be considered,
in shared global cache applications, such as Oracle RAC, to be an I/O subsystem for inter-node
global cache buffer transfers with the latency and bandwidth requirements of high performance
cluster computing.
* The interconnect network is a private network using a switch (or multiple switches) that only the
nodes in the cluster can access.
And
Oracle Clusterware requires that you connect the nodes in the cluster to a private network by way
of a private interconnect. The private interconnect is a separate network that you configure
between cluster nodes. The interconnect used by Oracle RAC is the same interconnect that
Oracle Clusterware uses. This interconnect should be a private interconnect, meaning it is not
accessible to nodes that are not members of the cluster.
Reference: Oracle Real Application Clusters (RAC) and Oracle Clusterware Interconnect Virtual
Local Area Networks (VLANs) Deployment Considerations