**Core Concept**
Generalized anxiety disorder (GAD) is a chronic condition characterized by excessive and persistent worry, fear, and anxiety that interferes with daily functioning. The pharmacological management of GAD involves the use of anxiolytics, antidepressants, and other agents to alleviate symptoms.

**Why the Correct Answer is Right**
Alprazolam, a benzodiazepine, is the drug of choice for GAD due to its rapid onset of action and efficacy in reducing anxiety symptoms. Alprazolam acts by enhancing the effect of gamma-aminobutyric acid (GABA) at the GABA_A receptor, leading to sedative, anxiolytic, and muscle relaxant properties. This mechanism of action results in a decrease in the activity of the central nervous system, which in turn reduces anxiety symptoms.

**Why Each Wrong Option is Incorrect**
**Option A:** Buspirone is an anxiolytic that is not a benzodiazepine and is not typically used as a first-line treatment for GAD. It works by interacting with serotonin receptors, but its onset of action is slower compared to benzodiazepines.
**Option C:** Venlafaxine is an antidepressant that is primarily used to treat major depressive disorder and social anxiety disorder. While it may have some anxiolytic effects, it is not the first-line treatment for GAD.
**Option D:** Beta-blockers are used to treat hypertension and certain cardiovascular conditions, but they are not effective in reducing anxiety symptoms in GAD.

**Clinical Pearl / High-Yield Fact**
When prescribing benzodiazepines like alprazolam for GAD, it's essential to consider the risk of dependence and withdrawal symptoms. A gradual tapering of the medication is crucial when discontinuing treatment to minimize the risk of rebound anxiety.

✓ Correct Answer: A. Alprazolam