【求助】windows2000 problem

2. You are the administrator of a Windows 2000 network. The network
consists of 30 Windows 2000 Professional computers and two Windows 2000
Server computers named Athens and Boston. Athens has a permanent cable
modem connection to the Internet.

All Windows 2000 Professional computers on the network are configured to
use Automatic Private IP Addressing (APIPA). The network does not contain
a DHCP server. To allow all Windows 2000 Professional computers on the
network to access the Internet through the cable modem connection of
Athens, you install and configure the Network Address Translation (NAT)
routing protocol on Athens. You decide to use IP addresses in the range of
192.168.40.1 through 192.168.40.50 for the network. Athens is configured
to use an IP address of 192.168.40.1. Boston is a Web server configured
with an IP address of 192.168.40.2 and a default gateway of 192.168.40.1.
Your Internet service provider (ISP) has allocated two IP addresses,
207.46.179.16 and 207.46.179.17, to your network.

The network is shown in the exhibit (Click the Exhibit button). You want
to allow Internet users from outside your internal network to use an IP
address of 207.46.179.17 to access the resources on Boston through the NAT
service on Athens.

How should you configure the network to accomplish this goal?

a. Configure Athens with a static route on the private interface of the
NAT routing protocol. Use a destination address of 207.46.179.17, a
network mask of 255.255.255.255, and a gateway of 192.168.40.2
b. Configure Boston with a static route on the U\.N interface. Use a
destination address of 192.168.40.1, a network mask of 255.255.255.255,
and a gateway of 207.46.179.17
c. Configure the U\.N interface of Boston to use multiple IP addresses
Assign the additional lP address of 207.46.179.17 to the interface.
d. Configure the public interface of the NAT routing protocol to use an
address pool with a starting address of 207.46.179.16 and a mask of
255.255.255.254. Reserve a public IP address of 207.46.179.17 for the
private IP address of 192.168.40.2

Answer:d
請問這條怎麼解釋答案是d呢?