Final answer:
In a dental setting, reservoirs for infectious agents can be contaminated instruments, patient records, and dental chairs; hence, the answer is d. All of the above.
Step-by-step explanation:
Items within a dental setting that can serve as reservoirs for infectious agents include contaminated instruments, such as dental tools, patient records, which may be touched by hands contaminated with pathogens, and dental chairs, which come into contact with patients and can harbor infectious agents. Therefore, the correct answer is d. All of the above. These reservoirs, known as fomites, are inanimate objects that may facilitate the transfer and growth of microorganisms. In the dental environment, strict sterilization and hygiene protocols are necessary to minimize the risk of infections, which can occur through exposure to these contaminated surfaces or instruments.