A client with chronic alcohol dependence is diagnosed with Wernicke's-Korsakoff's syndrome. The client is experiencing memory loss and confusion. Which medication should the nurse administer to help alleviate the client's symptoms?

Wernicke-Korsakoff syndrome is caused by a severe deficiency of thiamine (Vitamin B1), which is common in chronic alcoholism due to poor nutrition and impaired absorption. Administering thiamine is the specific treatment to address the underlying neurological damage responsible for the confusion and memory loss. Carbamazepine (A) is an anticonvulsant, clonidine (B) is used for hypertension and opioid withdrawal, and chlordiazepoxide (C) is a benzodiazepine used for alcohol withdrawal management; none of these address the thiamine deficiency causing the syndrome.