A visitor plugs a laptop into a network jack in the lobby and is able to connect to the company's network. Which of the following should be configured on the existing network infrastructure to best prevent this activity?

Port security is the best solution because it allows administrators to control which devices can connect to a network port, often by MAC address. If an unauthorized device, like the visitor's laptop, attempts to connect, the port can be disabled or restricted. A web application firewall protects web applications from attacks, not network access. Transport Layer Security (TLS) encrypts communication between a client and server, but doesn't prevent unauthorized physical network access. A Virtual Private Network (VPN) creates a secure, encrypted tunnel over an untrusted network, but doesn't control initial physical access to the internal network.