Which substances are considered controlled substances?

Controlled substances are defined by their inclusion in specific regulatory schedules that categorize them based on their accepted medical use, potential for abuse, and safety or dependence risk. In the context of the question, option B accurately reflects that any drug included in schedules I to V is considered a controlled substance.

These schedules encompass a wide range of substances. Schedule I includes drugs with no accepted medical use and a high potential for abuse, such as heroin and LSD. Schedules II through V contain drugs that have accepted medical uses but vary in their potential for abuse and dependence, ranging from high (Schedule II) to low (Schedule V). This classification serves to regulate the manufacture, distribution, and use of these substances to mitigate risks associated with misuse.

Other options do not encompass the full scope of what constitutes controlled substances. For instance, focusing solely on illegal drugs or prescription medications excludes the broader category of controlled substances, which also includes various medications with specific restrictions. Natural herbal supplements are generally not classified as controlled substances unless specifically designated under the relevant schedules.