**Core Concept**
Benzodiazepine antagonists are a class of medications that counteract the effects of benzodiazepines, a group of psychoactive drugs prescribed to treat anxiety, insomnia, and seizures. These antagonists can be useful in reversing benzodiazepine overdose or in patients with benzodiazepine dependence.

**Why the Correct Answer is Right**
Flumazenil is a selective benzodiazepine receptor antagonist that competes with benzodiazepines for binding sites on the GABA_A receptor. By occupying these sites, flumazenil prevents the action of benzodiazepines and can rapidly reverse their effects on the central nervous system. This mechanism of action makes flumazenil a useful antidote in cases of benzodiazepine overdose.

**Why Each Wrong Option is Incorrect**
* **Option A:** None provided. (We'll proceed with the other options)
* **Option B:** This option is not a benzodiazepine antagonist; it might be a benzodiazepine itself or a different class of medication.
* **Option C:** This option is not a benzodiazepine antagonist; it might be a medication used to treat a different condition or a different class of drugs altogether.
* **Option D:** This option is not a benzodiazepine antagonist; it might be a medication used to treat a different condition or a different class of drugs altogether.

**Clinical Pearl / High-Yield Fact**
Flumazenil is a short-acting benzodiazepine antagonist, making it useful in emergency situations. However, it can also precipitate seizures in patients who have not been exposed to benzodiazepines, so its use should be carefully considered.

**Correct Answer:** B. Flumazenil