A young client is admitted to the hospital directly from the clinic. The physician suspects a problem with the child's immune system. What test does the nurse anticipate the physician will order for this client?

Choice A rationale An X-ray is a form of imaging used to visualize bones and soft tissues, which would be ordered to assess for structural problems or infection in organs like the lungs, but it is not the primary initial test for evaluating the overall function of the immune system. Choice B rationale An Electrocardiogram (EKG) is a diagnostic test that records the electrical activity of the heart, used to assess cardiac rhythm and function, and it would not be the initial test to investigate a suspected disorder of the body's immune defenses. Choice C rationale A urine analysis is a test that examines the physical, chemical, and microscopic properties of urine, primarily used to detect conditions like urinary tract infections or renal disease, and does not provide comprehensive information on immune status. Choice D rationale A Complete Blood Count (CBC) is anticipated because it provides a quantitative measure of white blood cells (WBCs), red blood cells (RBCs), and platelets, offering critical initial insights into the number and differential count of leukocytes, which are the main components of the immune system.