Which of the following medications is a sedative?

Xanax is classified as a sedative because it belongs to a group of medications known as benzodiazepines. These drugs work by enhancing the effect of the neurotransmitter gamma-aminobutyric acid (GABA) in the brain, which leads to a calming effect on the nervous system. As a result, Xanax is commonly prescribed for anxiety and panic disorders due to its sedative properties. This calming effect can help patients feel more relaxed and less anxious.

In contrast, the other medications listed do not have sedative properties. Aspirin is primarily an analgesic and anti-inflammatory medication used to relieve pain and reduce inflammation. Propranolol is a beta-blocker used to treat cardiovascular issues such as hypertension and anxiety but does not induce sedation. Clopidogrel is an antiplatelet agent used to prevent blood clots and has no sedative effects. Therefore, Xanax stands out as the only sedative among the choices provided.