A nurse is assessing a client's coccyx area and notes visible subcutaneous fat with tunneling. Which of the following pressure injury stages should the nurse document?

A. Unstageable: An unstageable pressure injury occurs when the full thickness of tissue loss is obscured by slough or eschar. Since subcutaneous fat and tunneling are visible in this case, the injury can be staged and is not unstageable. B. Stage 2: Stage 2 pressure injuries involve partial-thickness skin loss with exposed dermis. They do not extend into subcutaneous tissue and do not present with tunneling or visible fat, so this stage does not fit the description. C. Stage 3: A Stage 3 pressure injury involves full-thickness skin loss. At this stage, subcutaneous fat (adipose tissue) is visible within the ulcer. Features like tunneling (a narrow opening or passageway extending from the wound) and undermining (tissue destruction underneath the intact skin at the wound edge) are common. However, the nurse should not be able to see bone, tendon, or muscle; if these deeper structures were visible, the injury would be classified as Stage 4. D. Stage 4: A Stage 4 pressure injury involves full-thickness skin and tissue loss. The distinguishing factor for Stage 4 is the direct visualization or palpation of fascia, muscle, tendon, ligament, cartilage, or bone within the ulcer. While tunneling can occur in Stage 4, the presence of only subcutaneous fat keeps this specific injury at Stage 3.