Which item should the nurse use first to assist in staging an ulcer on the heel of a darkly pigmented skin patient?

The correct answer is C: Natural light. Staging an ulcer requires accurate assessment of the wound, including color, depth, and tissue condition. Natural light provides the most accurate representation of colors, which is crucial for determining the stage of the ulcer on a darkly pigmented skin patient. Using artificial light sources may distort colors and affect the nurse's ability to accurately stage the ulcer. Disposable measuring tape (A) may be needed to measure the ulcer's size, but accurate color assessment is the priority. Cotton-tipped applicator (B) and sterile gloves (D) are not directly related to ulcer staging.