The Most Realistic Way to Prevent Bioterrorism Directed Against the Food

The most realistic way to prevent bioterrorism directed against the food supply is:

A) Post armed federal guards at all food and water processing facilities in the United States
B) Mandate all food and water products produced in, or imported into, the United States be laboratory tested for safety
C) Continuously inspect all food and water processing in the United States
D) Improve surveillance systems so that food- and waterborne disease outbreaks are detected early enough to intervene