Which one of the following statements BEST describes the action of AZT (azidothymine) on delaying the onset of symptoms and prolonging the lives of those infected with HIV?
AZT has a 5' $-OH$ group, so it can be incorporated into a growing polynucleotide chain. However, because it lacks a 3' $-OH$ group, the chain cannot be extended beyond it, and synthesis of the viral DNA stops before the chain is complete.
AZT is similar to thymine, which makes it easier to incorporate into the virus DNA.
AZT kills the virus by stopping the growth of the cell wall of the virus.
AZT is not very efficient for the treatment of the HIV.
AZT inhibits the reverse transcriptase enzyme, which makes the synthesis of viral DNA difficult. Once the virus DNA synthesis is inhibited, it cannot attack the immune system of the host further.