Which statement best describes a systematic approach to troubleshooting electrical problems?

Which statement best describes a systematic approach to troubleshooting electrical problems?

• A. Define the problem, gather data, and implement a fix immediately without testing.
• B. Gather data, then guess and replace components until it works.
• C. Verify the fix first, then gather data and define the problem.
• D. Define the problem, gather data, establish a theory, test the theory, implement a fix, verify, and document.

Answer: (D)