11. Hepatocellular carcinoma (Hepatoma) may be caused by

A. Hepatitis A virus
B. Hepatitis C virus
C. Both (a) and (b)
D. None of these

12. The defective satellite virus is

A. hepatitis B
B. hepatitis C
C. hepatitis D
D. hepatitis A

13. All of the following viruses are enveloped except

A. Hepatitis A virus
B. Hepatitis B virus
C. Hepatitis C virus
D. Hepatitis D virus

14. The diagnosis of hepatitis A virus infection is carried out from the method based on

A. aminotransferase levels
B. detection of faecal HAV by immunoelectron microscopy
C. both (a) and (b)
D. detection of IgM anti-HAV by ELISA

15. Which of the following is not correct for the hepatitis A virus?

A. It can be grown in cell cultures of primate and human cells
B. It is one of the most stable viruses infecting humans
C. It may cause hepatocellular carcinoma
D. None of the above