Final answer:
Infants are a group at high risk for foodborne illnesses, especially when exposed to pathogens found in contaminated foods such as oysters. Certain populations are more vulnerable due to age or compromised immune systems, with severe cases necessitating medical care.
Step-by-step explanation:
Among the options provided, infants (b) represent a group of people at high risk for foodborne illnesses. These illnesses can affect anyone; however, certain groups such as pregnant women, young children, older adults, and individuals with compromised immune systems due to medical conditions like diabetes, liver disease, kidney disease, organ transplants, HIV/AIDS, or treatment like chemotherapy or radiation are particularly at risk. Most cases resolve without medical intervention, but severe symptoms require immediate medical attention.
Regarding the occurrence of individuals becoming ill after eating oysters, a plausible hypothesis could be that the oysters were contaminated with a pathogen such as Norovirus or Salmonella, both of which are among the top five germs causing foodborne illnesses in the United States. Others include Clostridium perfringens, Campylobacter, and Staphylococcus aureus (Staph). Epidemiological investigations and case-control studies, like the ones mentioned in the reference, are critical for identifying the specific source of contamination in such events.