When You Verify a System Is Functioning Properly, You Determine

When you verify a system is functioning properly, you determine that the problem could have been prevented.
What should you do to help the computer's user avoid having the same problem again?

A) Lock the user out of the problem area.
B) Instruct the user on how to prevent the problem.
C) Don't tell the user anything so that he will have to call you back when the problem occurs again.
D) Document the problem and hope the user reads your notes.