Final answer:
The nurse should evaluate whether the decision was effective in achieving the desired outcome.
Step-by-step explanation:
The question that should best guide the nurse's evaluation process after making a decision is: Was the decision effective in achieving the desired outcome? By asking this question, the nurse-manager can assess whether the decision was successful in achieving the intended goal. For example, if the decision was to implement a new medication administration procedure, the nurse can evaluate if the procedure resulted in improved patient safety and medication adherence.