What is the cause of the spread of health epidemics such as HIV-AIDS, bird flu, etc?

All of the above.

The correct answer is Option 4 - All of the above.

Option 1- Migration
Option 2- Business
Option 3- Tourism
Option 4- All of the above

Health epidemics such as HIV-AIDS, bird flu, and severe acute respiratory syndrome (SARS) have rapidly spread across countries through migration, business, tourism, and military operations.