A nurse has taught parents about diagnostic testing for their child who is suspected of having leukemia. What test described by the parents shows good understanding of this information?

Choice A rationale Bone marrow aspiration and biopsy is the definitive diagnostic test for leukemia. This procedure involves extracting a small sample of the bone marrow, typically from the iliac crest in children, to analyze the type and percentage of immature blood cells (blasts) that characterize leukemia, thus confirming the diagnosis accurately. Choice B rationale A Computed Tomography (CT) scan uses X-rays to create cross-sectional images of the body. While useful for assessing solid tumors or detecting intracranial or chest disease complications of leukemia, it is not the primary or definitive diagnostic test for the condition itself, which is a cancer of the blood and bone marrow. Choice C rationale A Complete Blood Cell Count (CBC) is a crucial screening tool that often suggests the presence of leukemia by revealing abnormal white blood cell counts (often high or very low) and possibly anemia or thrombocytopenia. However, the CBC alone cannot confirm the diagnosis; it only indicates the need for definitive testing. Choice D rationale A Lumbar Puncture (spinal tap) is performed to collect cerebrospinal fluid (CSF) to check for the presence of leukemic cells that may have infiltrated the central nervous system, which is essential for staging and treatment planning, but it does not confirm the initial diagnosis of leukemia in the bone marrow.