which of the following is the BEST way to troubleshoot aproblem?

When making changes to a server, which of the following is the BEST way to troubleshoot a

problem?

A.
Perform root cause analysis and then test the theory to determine the cause.

B.
Make changes to the system and document everything once the problem is resolved.

C.
Make multiple changes to all affected areas to resolve all potential issues.

D.
Make a change and if the problem is not resolved, reverse the change.