What is an alternative configuration if proxy ARP cannot be used on your Security Gateway?

You want to implement Static Destination NAT in order to provide external, Internet users access
to an internal Web Server that has a reserved (RFC 1918) IP address. You have an unused valid
IP address on the network between your Security Gateway and ISP router. You control the router
that sits between the firewall external interface and the Internet.
What is an alternative configuration if proxy ARP cannot be used on your Security Gateway?

A.
Publish a proxy ARP entry on the ISP router instead of the firewall for the valid IP address.
B. Place a static ARP entry on the ISP router for the valid IP address to the firewall’s external
address.

C.
Publish a proxy ARP entry on the internal Web server instead of the firewall for the valid IP
address.

D.
Place a static host route on the firewall for the valid IP address to the internal Web server.