Final answer:
A nurse should instruct an AP to choose a larger cuff for blood pressure measurement in an obese client to ensure accurate readings.
Step-by-step explanation:
The information that a nurse should provide to an Assistant Personnel (AP) regarding obtaining blood pressure in an obese client is to choose a larger cuff for accuracy in blood pressure measurement. Using a cuff that is too small can result in a falsely elevated blood pressure reading. Whereas a larger cuff, that is appropriately sized to the circumference of the obese client's arm, will ensure the most accurate measurement.