C: Initiate the system restore:
If the technician is confident that rolling back the system to a previous restore point will resolve the issue, the next logical step is to initiate the System Restore process.
System Restore allows the system to revert to a state before the OS update, which can eliminate the performance issues caused by the update.
Incorrect Options:
A: Document the findings: Documentation is important but should occur after resolving the issue.
B: Investigate any recent infrastructure changes: This is unnecessary if the issue is already attributed to the OS update.
D: Verify full system functionality: This step should be performed after the System Restore is completed.
Key Takeaway: When confident that rolling back will resolve the issue, the technician should proceed with initiating a System Restore to revert the OS.
Reference: CompTIA A+ Core 1 Exam Objectives (220-1101), Domain 5.4 - Troubleshooting OS problems.