Final answer:
The rescuer needs to uncover the injury to fully assess it, which is option D. Uncovering allows for a visual examination to evaluate the nature and extent of the injury, crucial for proper first aid.
Step-by-step explanation:
Upon finding an injury, the rescuer needs to uncover the injury to fully assess it. The correct option is D. Uncover. By uncovering the injury, it allows the rescuer to see the extent of the injury, assess for any bleeding, foreign objects, or other concerns. Furthermore, uncovering the injury will enable the rescuer to determine the most appropriate first aid measure to apply, such as cleaning the wound, applying pressure if there is bleeding, or immobilizing a sprained or broken limb.
Ignoring the injury would not help in assessment or aid, while elevating and stabilizing are subsequent steps after the injury has been uncovered and properly assessed.