What could be the cause of this issue?

During a node add procedure the new node cannot be discovered. A ping to the IPv6 address is responding.

What could be the cause of this issue?
A . Only one network interface is up on the new node
B . vSAN VLAN is not configured correctly
C . Management VLAN ID is not set on the vmk0 interface
D . Loudmouth process is not running

Answer: A