Which of the following statements best defines 'narcotics' in the context of controlled substances?

The definition of 'narcotics' primarily refers to substances that relieve pain and have sedative properties, which aligns perfectly with the provided answer. Narcotics, particularly those that are classified as opioids, have medical uses for pain management but also exhibit effects that can lead to sedation or sleep induction. In this context, the understanding that narcotics are often associated with these characteristics is crucial for recognizing their role in both therapeutic settings and potential for misuse.

In contrast, the other options describe different categories of substances. Drugs that can induce hallucinations pertain more to hallucinogens, which affect perception and cognition rather than primarily serving as pain relief. Stimulants that enhance alertness are generally categorized as stimulants, which act by increasing activity in the central nervous system, a property contrary to the sedative effects of narcotics. Lastly, substances derived from cannabis plants are classified under cannabinoids, and while they may have pain-relieving properties, they do not fall under the traditional definition of narcotics. Understanding these distinctions is essential for recognizing the specific classification and legal definitions surrounding various controlled substances.