A 23-year-old male presents to the urgent care clinic complaining of sore throat, fever, and body aches. He reports that the illness began about 1 week ago and has persisted despite therapy with NSAIDs, acetaminophen, and sore throat lozenges. He has not sought medical advice for this condition previously. He denies cough, abdominal pain, nausea, or vomiting, but reports a persistent headache. His past medical and surgical history is unremarkable. The patient smokes about 1 pack of cigarettes a week, drinks occasional alcohol, and denies other drugs, including intravenous use. He is heterosexual, and has had 3 sexual contacts in the past year. On exam his vital signs are: T 38.9Â° C; P 112; BP 115/68; R 20. General: well-nourished male who appears uncomfortable. Head, ears, eyes, and nose are unremarkable. The patient has pharyngitis and enlarged tonsils with exudates. There is diffuse cervical lymphadenopathy, but the neck is supple. There are enlarged nodes in his axilla and inguinal areas as well. The spleen is palpable and nontender. The rest of the exam is unremarkable. In addition to a throat culture, blood count, and Mono Spot, an appropriate laboratory test to rule out the acute retroviral syndrome would be: A) HIV-1 antibody by ELISA and Western blot. B) HIV-1 antibody by rapid detection method. C) HIV-1 p24 antigen or HIV viral load by PCR. D) CD4 T lymphocyte count. E) Sperm centrifuge for viral culture.