<prompt>  With reference to the treatment of chronic Hepatitis B infection, consider the following drugs - 1. Lamivudine, 2. Alpha interferon, 3. Ribavirin, 4. Acyclovir. Which of the above drugs are useful in the treatment of chronic Hepatitis B infection ?1 and 2 only1 and 3 only2 and 3 only1, 2, 3 and 4 