Final answer:
The CNA's first response should be to document and report the bruising to a supervisor or nurse.
Step-by-step explanation:
The CNA's first response should be to document the bruising and report it to a supervisor or nurse. This is because unexplained bruising on a child may indicate physical abuse or another underlying issue that requires attention.
By documenting the bruising and reporting it, the CNA ensures that the appropriate action is taken to investigate and protect the child. It is important for healthcare professionals to prioritize the safety and well-being of their patients, especially when there are signs of potential harm.
In addition to reporting the bruising, the CNA should also make sure to continue providing care and support to the child during the bathing process, ensuring their comfort and safety.