Food borne illnesses can often be traced back to which of the following factors?

Foodborne illnesses can indeed be traced back to multiple contributing factors, which is why "all of the above" is the correct choice. Each of the factors mentioned plays a significant role in the transmission of harmful pathogens.

Poor personal hygiene is a critical factor. When food handlers do not maintain proper hygiene, such as not washing their hands after using the restroom or handling raw food, they can contaminate food with bacteria, viruses, or parasites. This can lead to outbreaks of foodborne illnesses.

Infrequent handwashing is also a significant contributor. Regular and thorough handwashing is essential in breaking the chain of infection. Food handlers must wash their hands frequently, especially after using the restroom, touching their face, or handling raw ingredients, to prevent the transfer of pathogens to food.

Inappropriate cooking temperatures are another important factor. Cooking food to the correct temperature kills harmful pathogens that may be present. If food is undercooked, it can harbor bacteria that survive and cause illness when consumed.

Considering all these points, it is clear that each of these factors contributes to the risk of foodborne illnesses, making the option that encompasses all of them the most comprehensive and accurate choice.