A nurse is providing care to a 4-year-old preschooler who has suspected lead poisoning. Which of the following actions should the nurse take first?

A. Prepare the child for venipuncture to obtain a blood sample for lead level testing: Confirming suspected lead poisoning requires measurement of a venous blood lead level. This diagnostic step is the priority because it establishes exposure severity and guides further management, including environmental interventions and possible chelation therapy. B. Discuss the need for developmental assessments to evaluate the impact of lead exposure: Developmental evaluation is important because lead exposure can cause cognitive and behavioral effects, but it is addressed after confirming the diagnosis and determining the extent of exposure. C. Document a detailed history of the child's growth and development, as well as manifestations of lead exposure: A thorough history supports overall assessment, but it does not take priority over obtaining objective laboratory confirmation needed to direct immediate care decisions. D. Instruct the parents to remove peeling paint and clean dust in the home to reduce the risk of lead exposure: Environmental control measures are essential, but education and remediation should follow confirmation of lead exposure and collaboration with public health resources.