A user is unable to access the internet but can still print to network printers.

When a single user is experiencing network issues while others are unaffected, the first step should always be to check the physical connectivity. This includes verifying that the Ethernet cable is plugged in properly, the NIC is enabled, and the link lights are active.

Option B (Reboot the router): Affects all users and is not necessary since others are not experiencing the issue.

Option C (Disable IPv6): Unlikely to resolve the problem unless you’re troubleshooting a specific IPv6-related issue.

Option D (Check the DNS settings): A valid step if internet access is limited to name resolution problems, but start with physical connectivity first.

? Reference:

CompTIA A+ 220-1102 Exam Objective 2.3 – "Given a scenario, troubleshoot common networking issues."

CompTIA Troubleshooting Methodology – Step 1: Identify the problem.