In April 2009, a new strain of influenza A emerged. This strain, known as the swine flu, caused at least 95 deaths in over 40 different countries. The rapid spread of this disease can be attributed to A. inadequate precautionary measures at the individual and community levels. B. a lack of immunity within individuals and the lack of an effective vaccine. C. globalization and the ease with which one can travel from country to country. D. all of these
