Refer to the exhibit. A newly configured PC fails to connect to the internet by using TCP port 80 to

An incorrect subnet mask might cause local or gateway connectivity issues, but DNS is more specifically related to hostname-based service access if an IP address is already obtained.

If a newly configured PC cannot connect to the internet using TCP port 80, implying web browsing, the most common reason, assuming basic IP connectivity, is that the DNS servers are incorrectly configured or missing. This prevents the PC from resolving website hostnames to IP addresses, thereby stopping the connection.

A missing default gateway would prevent *any* communication outside the local subnet. While critical, DNS is the specific service preventing name-based access.

DHCP servers provide IP configuration. If the PC has an IP address and is newly configured, the DHCP server has likely already done its job, or the configuration is static. This isn't the direct cause of a specific port 80 failure if an IP is present.