Which enzyme is responsible for integrating the viral $DNA$ (formed after reverse transcription of viral $RNA$) into the host cell $DNA$?

Which of the following is considered the factory for $HIV$?

Consider the following statements about $AIDS$.
$I.$ $AIDS$ patient become easily infected by bacteria,viruses and even parasites.
$II.$ The person is unable to protect himself against any infection.
$III.$ National $AIDS$ Control Organisation $(NACO)$ and non-governmental organizations are trying their best to educate people about $AIDS$.
Which of the statements given above are correct?

What is the full form of $NACO$?

Arrange the following statements regarding $AIDS$ in the correct chronological order of the infection process:
$(1)$ After entering the individual's body,the $HIV$ virus enters macrophages,where the viral $RNA$ genome replicates into viral $DNA$ with the help of the reverse transcriptase enzyme.
$(2)$ $HIV$ enters helper $T$-lymphocytes.
$(3)$ $HIV$ has an $RNA$ molecule as its genetic material.
$(4)$ Newly formed viruses are released into the blood and attack other helper $T$-lymphocytes.
$(5)$ Viral $DNA$ is incorporated into the host cell's $DNA$.

Which cells does $HIV$ primarily infect and destroy?