**Core Concept**
The detection of poisons from burnt bones is a notable aspect of forensic toxicology. This concept relies on the unique properties of certain substances that allow them to persist even after exposure to high temperatures. **Chlorine** is one such substance that can be detected from burnt bones.

**Why the Correct Answer is Right**
Chlorine is a highly reactive element that can bind to organic matter, including bones. Even when bones are burnt, the chlorine can persist in the form of **chloride ions**, which can be detected using various analytical techniques. This property makes chlorine an important substance to consider in forensic investigations, particularly in cases where the remains of a body have been subjected to high temperatures.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not specify a substance that can be detected from burnt bones. While some elements like **sodium** and **potassium** can be found in burnt bones, they are not typically associated with poisoning.
* **Option B:** This option is incorrect because it does not mention a substance that can be detected from burnt bones. **Cadmium**, a heavy metal, is not typically associated with the detection of poisons from burnt bones.
* **Option C:** This option is incorrect because it does not specify a substance that can be detected from burnt bones. While **arsenic** is a well-known poison, it is not typically associated with the detection of poisons from burnt bones.

**Clinical Pearl / High-Yield Fact**
In forensic toxicology, the detection of substances from burnt bones can be crucial in determining the cause of death. This is particularly important in cases where the remains of a body have been subjected to high temperatures, making it necessary to use specialized techniques to detect the presence of poisons.

**Correct Answer: C. Chlorine**