Final answer:
The best nursing intervention to correct the unmet outcome of a client trying to reduce their smoking to only half a pack a day is to revaluate the time frame originally decided upon for achievement of the goal.
Step-by-step explanation:
The best nursing intervention to correct the unmet outcome of a client trying to reduce their smoking to only half a pack a day is to revaluate the time frame originally decided upon for achievement of the goal. This means that the client and the nurse should discuss and review the timeline established for reaching the goal and make any necessary adjustments. This approach allows for a collaborative effort and helps the client to reassess their progress and set realistic expectations.