A nurse is admitting a child with a suspected diagnosis of Wilm's tumor. The nurse should place a sign with which of the following warnings about this child?

A. Wilms' tumor is a kidney tumor, and the child should not have blood pressure measured or venipuncture done on the affected side to avoid any potential injury to the kidney. B. This is important in care but is not the primary immediate precaution. The main focus is to avoid injury to the affected kidney. C. While urine collection is important for monitoring kidney function, it is not a warning sign for Wilms' tumor. D. This may be necessary later in the treatment but is not a primary concern for the initial care of a child with Wilms' tumor.