The CompTIA troubleshooting methodology includes steps like identifying the problem, establishing a theory of probable cause, testing the theory, creating a plan of action, implementing the solution, verifying functionality, and documenting findings. Establishing a theory involves analyzing the problem and considering possible causes, often by systematically checking each level of the OSI model (Physical, Data Link, Network, etc.) to pinpoint the root cause.
Why not Implement the solution? This step involves applying the fix, not analyzing the OSI model.
Why not Create a plan of action? This step focuses on planning the solution, not diagnosing the cause.
Why not Verify functionality? This step confirms the solution worked, not analyzing the OSI model.
Reference:CompTIA Network+ N10-009 Objective 5.2: Explain the troubleshooting methodology. The CompTIA Network+ Study Guide (e.g., Chapter 13: Network Troubleshooting) details the troubleshooting steps, noting that establishing a theory often involves using the OSI model to systematically identify the cause of network issues.