For a child diagnosed with a Wilm's tumor. The nurse recognizes that which of the following is MOST important intervention when planning care for this child?

A. Avoiding further palpation of the abdomen is crucial to prevent rupture of the tumor and potential spread of cancer cells. B. Obtaining an accurate height and weight is important but not as critical as preventing tumor rupture. C. Monitoring vital signs is essential but not the priority intervention in this context. D. Assessing the urine for the presence of blood is important for overall assessment but not the most critical intervention compared to avoiding tumor rupture.