The only oncogenic virus whose pathogenicity has been proved without doubt is -: (A) HTLV - I, (B) HTLV - II, (C) HTLV - III, (D) HTLV - IV
Answer is A. HTLV1 present world wide.it causes adult T cell leukemia,tropical dpadtic paraparesid.it mainly infect CD4 cells .infected cell express more inter leukin2 REF:<\p>MICROBIOLOGY ANANTHA NARAYANAN NINTH EDITION PAGE.567