Which troubleshooting approach is more appropriate for a seasoned network administrator rather than a less-experienced network administrator?

Question:
Which troubleshooting approach is more appropriate for a seasoned network administrator rather than a less-experienced network administrator?

• a less-structured approach based on an educated guess
• an approach comparing working and nonworking components to spot significant differences
• a structured approach starting with the physical layer and moving up through the layers of the OSI model until the cause of the problem is identified
• an approach that starts with the end-user applications and moves down through the layers of the OSI model until the cause of the problem has been identified

Exam with this question: CCNA 3 v7.0 Final Exam Answers