Final answer:
Palpation of the abdominal midline area in a patient with an abdominal aortic aneurysm requires further education because it can lead to a life-threatening rupture.
Step-by-step explanation:
The correct assessment technique for a client with an unrepaired abdominal aortic aneurysm (AAA) is crucial to avoid causing any potential harm. The technique that requires further education by the supervising nurse is d. Palpation of the abdominal midline area. Palpation can potentially rupture the aneurysm, which is a life-threatening emergency. Measurement of abdominal girth, observation of abdominal wall movement, and auscultation of the abdomen are appropriate and non-invasive assessment techniques that do not pose a risk to the integrity of an AAA.