A food borne illness outbreak occurs when ____ or more people get sick after eating a _____ food.

A foodborne illness outbreak is defined as an occurrence where two or more people experience the same illness after consuming the same contaminated food or beverage. The correct answer emphasizes the requirement of multiple individuals being affected, which indicates that the illness is not isolated to one person and suggests a common source or issue with the food involved.

The choice of "similar" food underscores the connection between the individuals' illnesses, which helps identify patterns and sources of contamination. It highlights the importance of epidemiological tracking in food safety to determine how widespread the issue may be and how it can be controlled or prevented.

In contrast, other options suggest varying numbers of individuals or other descriptors of food safety that do not align with the recognized definitions of outbreaks. For instance, referencing "1" would indicate a singular incident rather than an outbreak, while terms like "spoiled," "contaminated," or "unsafe" alone do not encapsulate the requirement for multiple cases resulting from shared consumption. Thus, the emphasis on “two” and the connection through “similar” food most accurately reflects the criteria for determining a foodborne illness outbreak.