Question: A 30-year-old male patient with a history of HIV infection has been on antiretroviral therapy (ART) since diagnosis at age 28 years. Which of the following indicates that the patient's immune system is responding to ART? Want Online Help? A. HIV viral load is higher compared with the previous test. B. CD4 count is higher compared with the previous test. C. Complete blood count (CBC) shows an increase in leukocyte count. D. Genetic testing of the patient's HIV strain shows that it is sensitive to current HIV regimen.