Which of the following would be classified as adulteration?

Adulteration refers to the practice of lowering the quality of a food product by adding inferior substances or diluting it with cheaper ingredients. In this context, adding filler substances to decrease costs is classified as adulteration because it compromises the integrity and quality of the food item. This action may deceive consumers regarding the actual value and nutritional content of the product, as the filler does not contribute to the food's intended properties.

The other options do not compromise the quality of the food in the same way. Fortifying a food item with vitamins is a practice aimed at enhancing the nutritional value, making it beneficial rather than adulterating it. Using organic ingredients aligns with consumer demand for natural and pesticide-free products and enhances the product's quality. Providing fresh packaging for food items ensures safety and quality preservation rather than altering the content itself. Thus, the incorporation of fillers specifically to reduce costs stands out as a clear violation of food integrity standards, making it the correct classification of adulteration.