Which of the following describes the unlawful use of a controlled substance?

The unlawful use of a controlled substance specifically pertains to the use of drugs or chemicals that are regulated by law due to their potential for abuse and addiction. This includes medications that have been classified as controlled by government regulations, which typically require a prescription for legal use. When an individual uses a controlled substance without appropriate authorization, such as a prescription from a licensed medical professional, this constitutes unlawful use.

This definition helps clarify that the behavior outlined in the correct choice specifically involves the misuse of substances that are not legally permissible, emphasizing both the legal aspect and the importance of following regulations regarding controlled substances. The other options do not accurately reflect the concept of unlawful use; for example, using any substance freely doesn’t consider legal implications, and taking prescribed medication is legal and often necessary for health. Similarly, using herbal supplements typically does not fall under the same legal constraints as controlled substances.