The nurse teaches a patient to self-administer his insulin. How can the nurse best evaluate whether the patient understands the instruction?

The correct answer is D: Observe as the patient prepares and injects a dose of insulin. This is the best way to evaluate whether the patient truly understands the instruction because it allows the nurse to directly assess the patient's ability to perform the task correctly in a real-life situation. By observing the patient, the nurse can see if the patient follows the correct procedure, demonstrates proper technique, and understands the necessary precautions. This method provides concrete evidence of the patient's comprehension and ability to self-administer insulin.

Choice A (Ask the patient an open-ended question about feelings related to the procedure) focuses on emotional aspects rather than practical understanding. Choice B (Ask the patient to repeat the information in the insulin pamphlet) tests memorization rather than application. Choice C (Have the patient list the steps of the procedure for insulin administration) assesses theoretical knowledge but does not confirm practical execution.