Which of the following is a Schedule IV controlled substance?

Zaleplon is classified as a Schedule IV controlled substance because it has a lower potential for abuse relative to substances classified under higher schedules. Schedule IV substances are recognized for having a valid medical use and typically exhibit a lower risk of dependence compared to Schedule I, II, and III substances. Zaleplon, primarily used as a sedative for the treatment of insomnia, meets these criteria.

The other substances listed, such as hydrocodone, morphine, and oxycodone, are classified as Schedule II controlled substances due to their higher potential for abuse and addiction. These medications are typically used for the management of severe pain but are subject to stricter regulations and prescribing guidelines compared to Schedule IV substances like zaleplon.