Which retrovirus is believed to cause cancer? (select all that

There are choices for this question namely:

a. Human immunodeficiency virus (HIV)
b. T-lymphocyte virus type I
c. Epstein-Barr virus
d. Parvovirus
e. Poxvirus

The correct answers are HIV, T-lymphocyte virus type I, and Epstein-Barr virus. HIV or human immunodefiency virus will predispose the patient in developing Kaposi sarcoma in later stages of acquired immunodeficiency syndrome. T-lymphocyte virus type I is believed to be the etiological agent for developing T-cell leukemia or lymphoma. Epstein-Barr virus is associated with both nasopharyngeal carcinoma and Burkitt lymphoma. 

Parvovirus B19 causes a viral exanthem called erythema infectiosum which has no propensity to malignancy. Poxvirus is the etiologic agent for molluscum contagiosum, also with no propensity in developing malignancy.