Which basic troubleshooting technique includes four levels of testing?

• A. Information Funneling
• B. Bracketing
• C. Block Diagrams
• D. Signal Flow

Answer: (A)

This is about a structured troubleshooting approach that uses a narrowing path through information and tests, organized into four levels. Information Funneling guides you to start with broad observations and questions, then progressively drill down through more specific checks and tests, until you can pinpoint the fault and verify the fix. That four-level sequence is what makes this technique the best fit for a question asking about a four-level testing scheme: you move from wide, general symptoms to targeted diagnostics and final confirmation, reducing uncertainty at each step.

Bracketing, block diagrams, and signal flow describe different ideas: bracketing is about setting bounds or ranges to isolate a parameter, block diagrams map out system components and their relationships, and signal flow traces how signals travel through the system. None of these by themselves define a four-level testing process.