Final answer:
The nurse is assessing the peripheral circulation by compressing the child's nailbed. This is part of a blanch test to check for normal blood flow to the extremities after the child received an arm cast. The correct option is D.
Step-by-step explanation:
The nurse compresses the nailbed of a child who has just received an arm cast to assess the peripheral circulation. This is done using a blanch test where the fingernail is pressed to force the blood out of the nail bed capillaries; on release, the color should return quickly if blood flow is normal.
If there is a delay, it may indicate issues like low blood volume or shock. Nail health can give insights into overall health, as changes in nail color or texture can indicate various health issues such as fungal infections or oxygen saturation levels.