Your company has 250 client computers connected to the office LAN. The company has a pool of five public IP addresses. All client computers have dynamically assigned IP addresses. You need to provide all client computers with Internet access.  What should you use？（）

• A、 DHCP Relay Agent
• B、 Routing Information Protocol （RIP）
• C、 Internet Group Management Protocol （IGMP）
• D、 Network Address Translation （NAT）/Basic Firewall