Which foodborne pathogen is the most common bacterial cause of foodborne illness? 

• A. Salmonella.
• B. E. coli.
• C. Norovirus.
• D. Listeria.

Answer: (C)

Verified step by step guidance

1. Understand that the question asks for the most common bacterial cause of foodborne illness, which means we need to identify the bacterial pathogen responsible for the highest number of cases.
2. Review the options given: Salmonella, E. coli, Norovirus, and Listeria. Note that Norovirus is a virus, not a bacterium, so it cannot be the correct answer for a bacterial cause.
3. Recall that Salmonella and E. coli are both common bacterial pathogens associated with foodborne illness, while Listeria is less common but can cause severe illness.
4. Compare the prevalence of Salmonella and E. coli in foodborne illness statistics, noting that Salmonella is generally recognized as the most common bacterial cause.
5. Conclude that the correct answer is Salmonella, as it is the most frequent bacterial pathogen causing foodborne illness, while Norovirus, although common, is viral and not bacterial.