Viral DNA after being converted from viral RNA by X, incorporates into host genome to undergo replication. What is ‘X’ ?

The correct option is D Reverse transcriptase
When HIV enters into the body of a person, it moves into macrophages where RNA genome of the virus replicates to form viral DNA with the help of enzyme reverse transcriptase. This viral DNA gets incorporated into the host cell’s DNA and directs the infected cells to produce more viruses. The macrophages producing viruses, thus act as HIV producing factories. Simultaneously HIV enters into helper T-cells where it replicates and produces other viruses. This is repeated so that the number of helper T-cells decreases in the body of the infected person.
So, X is- Reverse transcriptase