Let's evaluate each statement about firewalls:1. "A packet filter firewall, filters at the datalink layer." This is FALSE. Packet filter firewalls operate at the network layer (Layer 3) and sometimes the transport layer (Layer 4) of the OSI model. They examine packet headers (like IP addresses and ports) to decide whether to allow or block traffic. They do not typically inspect or filter at the datalink layer (Layer 2).2. "A firewall is a device installed between the internal network of an organization and the rest of the Internet." This is TRUE. This is a common placement for firewalls, acting as a perimeter defense.3. "A firewall can be used to deny access to a specific host in the organization." This is TRUE. Firewalls can enforce granular access control policies, including blocking traffic to or from specific internal hosts.4. "A firewall can act as a proxy-based firewall." This is TRUE. Proxy firewalls (also known as application-layer firewalls) act as intermediaries for network connections, inspecting traffic at the application layer and offering more advanced security features.Therefore, the false statement is the first one.