This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Unknown
A HBsAg and anti-HBc (IgG) positive chronic hepatitis patient was also diagnosed to have HIV infection.  Best drug to attack both the viruses is 
Select and explain. 
A. Zidovudine, B. Tenofovir, C. Stavudine, D. Abacavir
B: Tenofovir
Answer: B: Tenofovir 
Explanation: Ref. KDT. Page. 808
Tenofovir is an adenine analog REVERSE TRANSCRIPTASE INHIBITOR with antiviral activity against HIV-1 and HEPATITIS B.

It is used to treat HIV INFECTIONS and CHRONIC HEPATITIS B, in combination with other ANTIVIRAL AGENTS, due to the emergence of ANTIVIRAL DRUG RESISTANCE when it is used alone.