What substances are listed under FDA Schedule D?

The correct choice pertains to substances classified as biologics and blood products. In the context of FDA regulations, biologics encompass a wide range of products derived from living organisms, including vaccines, blood components, and cellular therapies. Blood products, specifically, are derived from human blood and are used for various therapeutic purposes. This classification under Schedule D reflects the rigorous standards and regulatory framework that apply to these products due to their complex nature and the vital role they play in health care.

In comparison, allergenic substances, while important for understanding how they are regulated, do not fall specifically under the FDA's Schedule D. Radiopharmaceuticals, which are used in nuclear medicine, have their own distinct regulatory considerations but are not categorized under Schedule D. Controlled substances are primarily regulated under a separate schedule related to their potential for abuse and dependence rather than being associated with biologics or blood products. Thus, the classification of biologics and blood products aligns accurately with the definitions and regulations established by the FDA.