The correct answer is B. Document the findings. In the troubleshooting methodology, after the issue has been resolved and functionality has been verified, the final step is to document the findings, lessons learned, actions, and outcomes. Testing the theory, creating an action plan, and implementing the action plan all happen before the problem is resolved.

Exact Extract/Reference: The CompTIA Tech+ Study Guide lists the troubleshooting steps in order: identify the problem, establish a theory, test the theory, establish a plan and implement the solution, verify full system functionality, and finally “Document findings/lessons learned, actions, and outcomes.”