## **Core Concept**
The question pertains to the management of cyanide poisoning, focusing on the use of specific salts that can bind to cyanide ions (CN-) to form less toxic compounds. The goal is to identify a non-toxic salt used in treating cyanide poisoning.

## **Why the Correct Answer is Right**
The correct answer, **. Sodium thiosulfate**, is used in the treatment of cyanide poisoning. It works by providing a sulfur donor for the enzyme **rhodanese** to convert cyanide into thiocyanate, which is much less toxic and can be excreted by the kidneys. This process effectively detoxifies cyanide.

## **Why Each Wrong Option is Incorrect**
- **Option A:** While certain nitrites can be used in the treatment of cyanide poisoning (as part of the cyanokit or by generating methemoglobin which binds CN-), the description here is incomplete, making it an incorrect choice without further specification.
- **Option B:** This option seems to refer to another treatment but is not clearly defined; however, **N-acetylcysteine** is not primarily known for its role in directly treating cyanide poisoning through the mechanism described.
- **Option D:** **Sodium nitrate** can be used in cyanide poisoning treatment to generate methemoglobin, which binds cyanide. However, it is not described as a "non-poisoning salt" in the context provided and can have other effects.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that **sodium thiosulfate** is often used in conjunction with nitrites (like sodium nitrite) for treating cyanide poisoning. The combination enhances the body's natural ability to detoxify cyanide. A classic regimen involves administering nitrites to generate methemoglobin, followed by thiosulfate to donate sulfur for the conversion of cyanide to thiocyanate.

## **Correct Answer:** . Sodium thiosulfate