Which substance listed is not a Schedule II drug?

Diazepam is classified as a Schedule IV controlled substance, which indicates that it has a lower potential for abuse compared to Schedule II drugs. Schedule II substances are recognized for having a high potential for abuse and may lead to severe psychological or physical dependence. Drugs like cocaine, mephedrone, and morphine sulfate fall into this category due to their significant risks associated with misuse and dependence. Consequently, the inclusion of diazepam as a Schedule IV drug solidifies its distinction from the other substances listed, which are categorized as Schedule II due to their higher risk classification in the context of controlled substances.