What is a characteristic of Class D narcotics?

Class D narcotics are typically characterized by substances that include both marijuana and certain barbiturates, which aligns with the correct answer. This classification acknowledges the unique regulatory framework surrounding these drugs that distinguishes them from other classes of narcotics.

Marijuana, a well-known substance, and barbiturates, which are central nervous system depressants, exemplify how Class D narcotics encompass a broader category of drugs that are subject to specific legal provisions. These substances are recognized for their varying levels of acceptability and regulation both medically and recreationally within different jurisdictions.

This answer highlights an important aspect of drug classification and reflects the complexities in how society and law treat various substances based on their effects, potential for abuse, and medical utility. Other options do not adequately reflect the characteristics that define Class D narcotics. For instance, while synthetic substances can be included in broader narcotic classifications, they are not specifically representative of Class D. Moreover, the focus on prescription drugs or federally regulated substances alone does not encompass the entire scope of what Class D narcotics represents.