Country Z Has the Lowest Incidence of HIV/AIDS of Any

Multiple Choice

Country Z has the lowest incidence of HIV/AIDS of any country in the world. However, people in Z who are diagnosed with HIV/AIDS die much more quickly than in other countries.
Which one of the following, if true, would most help resolve the apparent paradox?

A) There are many forms of HIV/AIDS that have different levels of prevalence.
B) Most of the cases of HIV/AIDS in Z are among immigrants.
C) In Z, testing for HIV/AIDS is infrequent and often does not catch the disease until it is very advanced.
D) The number of HIV/AIDS cases fluctuates every year.
E) Z has high rates of other diseases, such as malaria.