Which drug is a controlled substance used for pain management?

Ultracet is the correct answer because it contains a combination of tramadol and acetaminophen, and tramadol is classified as a Schedule IV controlled substance due to its potential for abuse and dependence. As a medication used for pain management, Ultracet effectively targets moderate pain while combining the analgesic effects of both tramadol and acetaminophen.

The other drugs listed do not fall under the classification of controlled substances for pain management. Telmisartan, for instance, is primarily used as an antihypertensive to treat high blood pressure and does not have pain-relieving properties. Lotrisone, which contains betamethasone and clotrimazole, is a topical medication used for treating fungal infections with inflammation but is not used for pain management and is not a controlled substance. Cephalexin is an antibiotic prescribed for bacterial infections and, like the other options, does not relate to pain management or substance control regulations. Thus, Ultracet stands out as the only option aimed at treating pain and recognized as a controlled substance.