Final answer:
The nurse would document this wound as a Stage 4 pressure injury.
Step-by-step explanation:
The nurse would document this wound as a c) Stage 4 pressure injury. Stage 4 pressure injuries involve full-thickness skin loss with exposed bone, tendon, or muscle. In this case, the nurse observes bone and tendon at the base of the wound, indicating a Stage 4 pressure injury. Stage 4 pressure injuries are the most severe and can be life-threatening if not properly treated.