Pest is defined as

• A. any insect, rodent or bird that may render a subsistence unwholesome
• B. all arthropods
• C. any mammal
• D. any plant

Answer: (A)

Pest in this context means the animals whose presence can contaminate or render food unwholesome, especially in storage or production environments. Insects, rodents, and birds are the typical pests because they can physically contaminate food with droppings, hair, nesting materials, or parasites, and they can introduce pathogens or cause spoilage. So defining a pest as any insect, rodent, or bird that may render a subsistence unwholesome directly targets the main sources of contamination risk in food safety. The other options are too broad or not aligned with this specific risk: all arthropods would include many harmless species; any mammal or any plant goes beyond the usual meaning of pests that threaten food wholesomeness.