Final answer:
The nurse should demonstrate the appropriate technique and re-educate the client's wife.
Step-by-step explanation:
The correct nursing action that the nurse should implement when observing the client's wife holding his arm above and below the elbow during passive range-of-motion exercises is option B) Demonstrate the appropriate technique and re-educate the wife.
This nursing action is necessary because holding the arm above and below the elbow during passive range-of-motion exercises can cause incorrect alignment and improper movement, which can lead to further injury or discomfort for the client. By demonstrating the correct technique and re-educating the wife, the nurse can ensure that the exercises are being performed correctly and safely.
For example, the nurse can show the wife how to properly hold the client's arm at the joint rather than above or below it. This will allow for optimal alignment and effective performance of the exercises.