Task: Question Answering
Input (English): Question: Which of the following vertebrate viruses does it require during its multiplication cycle of a polymerase with reverse transcriptase activity? 
 Options:  <1> Herpes simplex virus type 1. <2> Smallpox virus <3> Varicella-zoster virus. <4> Hepatitis B virus <5> Epstein-Barr virus.
Output (English): 4