This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Virology (General Propeies, DNA Viruses), Subject name: Microbiology
A 14-year-old boy presents at your office with a sore throat, fever, and enlarged lymph nodes. His tonsils are enlarged, the pharynx is inflamed, and splenomegaly is observed. He complains of severe fatigue. Confirmation of the causative agent is best done by observing 
Select and explain. 
A. A positive Tzanck smear, B. IgM heterophile antibodies, C. Koilocytotic cells, D. -PCR for Enterovirus.
B: IgM heterophile antibodies
Answer: B: IgM heterophile antibodies 
Explanation: This boy's symptoms are consistent with infectious mononucleosis caused by EBV (Epstein Barr Virus). During its pathogenesis, this virus produces an IgM heterophile antibody that is the basis for the Monospot test. Option 1: A positive Tzanck smear : Tzanck cells (acantholytic cells) are found in: Herpes Simplex Varicella and Herpes Zoster Pemphigus vulgaris Cytomegalovirus Option 3: Koilocytes, also known as halo cells, are a type of epithelial cell that develops following a human papillomavirus (HPV) infection.