All of the choices are the challenges that countries face in limiting the spread of communicable diseases. The lack of available healthy food would force countries to increase its reliance on food producers abroad, which could mean food contamination during harvesting, storage, processing, and transport.
Next, the increase of worldwide travel has also increase the risk of infectious disease where travelers encounter microbes in the new environment and can have direct contact with exotic wildlife.
Moreover, the decrease of available clean water is a source of communicable diseases because inadequate sewage and water management systems could incubate disease vectors such as mosquitoes and rats. Also, improper sanitation services spread diarrheal diseases.
Lastly, the increase in migration of infected animals are also a good source of infectious diseases for animals that are introduced in new environment can disrupt ecosystems in ways that increase the potential for infectious disease outbreaks such as Ebola and Lyme diseases.
