Which of the following defines animal by-products?

• A. animal products used as ingredients in non-meat products
• B. products derived from plants used in animal feed
• C. meat products sold as primary dietary items
• D. substances produced by animals that are only used in fertilizer

Answer: (A)

Animal by-products are materials that come from animals but aren’t the primary meat items sold for human consumption. They’re used as ingredients in a variety of non-meat products, such as gelatin, absorbent fats, and other animal-derived components found in foods, cosmetics, and industrial items. That makes this option the best fit. The other choices don’t describe by-products: plant-derived materials used in animal feed aren’t animal by-products; meat products sold as the main dietary item are exactly the primary meat items, not by-products; and limiting by-products to fertilizer ignores the many other uses in foods and non-food products.