In which situation is NAT proxy NDP required?

A.
when translated addresses belong to the same subnet as the ingress interface

B.
when filter-based forwarding and static NAT are used on the same interface

C.
when working with static NAT scenarios

D.
when the security device operates in transparent mode

Explanation:
When IP addresses are in the same subnet of the ingress interface, NAT proxy ARP configured
http://www.juniper.net/techpubs/en_US/junos12.1×44/information-products/pathway- pages/
security/security-nat.pdf
http://www.juniper.net/techpubs/en_US/junos-space12.2/topics/concept/junos-space- securitydesigner-whiteboard-nat-overview.html