In which situation is NAT proxy NDP required?
A.
when the security device operates in transparent mode
B.
when translated addresses belong to the same subnet as the ingress interface
C.
when filter-based forwarding and static NAT are used on the same interface
D.
when working with static NAT scenarios
B is correct
When IP addresses are in the same subnet of the ingress interface, NAT proxy ARP configured
http://chimera.labs.oreilly.com/books/1234000001633/ch09.html#nat_rules
Option B
If the translated address is in the subnet of the egress interface then proxy is required.