The correct answer is Both I and II.Packet filtering firewalls:As the most œbasic and oldest type of firewall architecture, packet-filtering firewalls create a checkpoint at a traffic router or switch.These work at the Network layer of the OSI networking model.The firewall performs a simple check of the data packets coming through the router inspecting information such as the destination and origination IP address, packet type, port number, and other surface-level information without opening up the packet to inspect its contents.Packet filter firewall operates at the network and transport layer. Hence, Statement 2 is correct.A proxy firewall:It is a network security system that protects network resources by filtering messages at the application layer. Hence, Statement 1 is correct.A proxy firewall is also be called an application firewall or gateway firewall.A proxy firewall is also a proxy server, but not all proxy servers are proxy firewalls.