In the U.S. it is often difficult to identify the source of a food-borne disease outbreak and stop it because
a. the food system is complex and food moves very quickly from farms to multiple consumers.
b. the U.S. government does not have any agency charged with reducing or stopping food-borne illness.
c. most food-borne diseases are caused by food imported from outside the U.S.
d. the technology to identify food-borne pathogens is too expensive for most public health agencies.