Which of the following is considered a Schedule IV substance?

Diazepam is classified as a Schedule IV controlled substance under the Controlled Substances Act. Schedule IV substances are considered to have a lower potential for abuse than those in Schedules I through III, and they have accepted medical uses in the United States. Diazepam, commonly known for its use in treating anxiety, muscle spasms, and seizures, fits this classification because it exhibits a lower risk for physical or psychological dependence compared to drugs in higher schedules.

In contrast, fentanyl is a very potent opioid that is classified as a Schedule II substance due to its high potential for abuse and risk of severe dependence. Oxycodone and hydrocodone are also classified as Schedule II substances for similar reasons. These drugs are available by prescription and are used for pain management but carry a high risk of dependency and abuse. Thus, among the options listed, diazepam stands out as the only Schedule IV substance.