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: Microbiology
HIV contains: March 2013 
Select and explain. 
A. Integrase, B. RNA directed DNA polymerase, C. Ribonuclease, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: Ans. D i.e. All of the above HIV virus It is composed of two copies of positive single-stranded RNA that codes for the virus's nine genes enclosed by a conical capsid composed of 2,000 copies of the viral protein p24. The single-stranded RNA is tightly bound to nucleocapsid proteins, p7, and enzymes needed for the development of the virion such as reverse transcriptase, proteases, ribonuclease and integrase. A matrix composed of the viral protein p17 surrounds the capsid ensuring the integrity of the virion paicle.