The specific antidote for benzodiazepine toxicity is Flumazenil. Benzodiazepines exert their effects by enhancing the activity of the neurotransmitter gamma-aminobutyric acid (GABA) at the GABA-A receptor. In cases of overdose or toxicity, this results in CNS depression, sedation, respiratory depression, and potentially coma.

- Flumazenil is a benzodiazepine receptor antagonist that competitively inhibits the binding of benzodiazepines at the GABA-A receptor.
- By doing so, it reverses the sedative and hypnotic effects of benzodiazepines rapidly and effectively.
- It is important to use flumazenil cautiously, as it can precipitate withdrawal seizures in patients with chronic benzodiazepine use or dependence.

The other options provided are antidotes for different toxicities:
- Naloxone is an opioid antagonist used for opioid overdose.
- Atropine is an anticholinergic agent used primarily for organophosphate poisoning or bradycardia.
- Physostigmine is a cholinesterase inhibitor used as an antidote in anticholinergic toxicity.

Therefore, for suspected benzodiazepine overdose, Flumazenil remains the specific and targeted antidote.

Reference: Goldfrank's Toxicologic Emergencies, 12th Edition, Chapter on Sedative-Hypnotic Agents, Page 541