According to troubleshooting methodology, which of the following should the technician do NEXT after determining the most likely probable cause of an issue?

According to troubleshooting methodology, which of the following should the technician do NEXT after determining the most likely probable cause of an issue?

A. Establish a plan of action to resolve the issue and identify potential effects B. Verify full system functionality and, if applicable, implement preventive measures C. Implement the solution or escalate as necessary D. Test the theory to determine the cause