Which of the following is a condition for a controlled substance to be classified under Schedule III?

In the context of the scheduling of controlled substances, Schedule III is characterized by substances that have a moderate potential for physical dependence or a high potential for psychological dependence. This classification reflects a balance between effective medical use and the risk associated with abuse.

The requirement for moderate potential for physical dependence is fundamental to this category. Schedules I and II typically consist of drugs that have a higher potential for abuse and dependence. Therefore, Schedule III substances must demonstrate a lesser degree of potential for dependence compared to those in the higher schedules while still being useful for medical purposes.

The other options do not align with the criteria for Schedule III. For instance, a greater potential for abuse than Schedule II or a low potential relative to Schedule I do not accurately reflect the characteristics required for Schedule III classification. Additionally, the requirement for approval in all states does not pertain to the classification criteria but rather to regulatory compliance at the state level.