A nurse is caring for a child who has retinoblastoma and is receiving chemotherapy. Which of the following findings should the nurse identify as an indication that the child is developing leukopenia from the treatment?

A. Lightheadedness or dizziness upon standing is typically associated with orthostatic hypotension or anemia, not directly with leukopenia. While chemotherapy can cause anemia, this finding is not specific for low white blood cell counts. B. Leukopenia, or a low white blood cell count, compromises the immune system, making the child more susceptible to infections, including ear infections, respiratory infections, and sepsis. The development of a new infection during chemotherapy is a key clinical indicator of leukopenia. C. This finding indicates thrombocytopenia, a low platelet count, which increases the risk of bruising or bleeding, rather than leukopenia. D. Gingival bleeding is typically associated with thrombocytopenia, not leukopenia. Low platelet counts impair clot formation, leading to bleeding from mucous membranes and skin, but this is distinct from infection susceptibility caused by low white blood cells.