Why Do Scientists Consider HIV to Be an Emerging Virus

Why do scientists consider HIV to be an emerging virus?

A) HIV infected humans long before the 1980s, but it has now mutated to a more deadly form.
B) HIV mutates rapidly making the virus very different from HIV in the early 1980s.
C) HIV suddenly became apparent and widespread in the 1980s.
D) HIV is now starting to cause diseases other than AIDS, such as rare types of cancers and pneumonias.
E) To infect, HIV originally required other concurrent viral infections in the host, however, now HIV can infect humans in the absence of other concurrent viral infections.