Final answer:
The USP/NF and the Homeopathic Pharmacopeia are the compendia officially recognized by the FDCA. The USP/DI is not legally recognized under the FDCA. Hence, the correct answer is e. b and c.
Step-by-step explanation:
The substances that are recognized by the Federal Food, Drug, and Cosmetic Act (FDCA) include the United States Pharmacopeia/National Formulary (USP/NF) and the Homeopathic Pharmacopeia of the United States. These compendia provide standards for the quality, purity, strength, and consistency of substances and are integral to the FDCA's regulatory framework to ensure the safety of drugs. The USP/DI, or USP Drug Information, is not a legally recognized compendium under the FDCA, unlike the USP/NF and the Homeopathic Pharmacopeia, which are officially recognized and enforceable by the FDA. Therefore, the correct answer to the question 'Which of the below is(are) officially recognized by the FDCA?' would be e. b and c, meaning the USP/NF and the Homeopathic Pharmacopeia are recognized by the FDCA.