**Core Concept**
Bleaching powder, also known as calcium hypochlorite, is a strong disinfectant and oxidizing agent used in various applications, including water treatment and as a bleaching agent. Its chemical formula is Ca(ClO)₂, and it is a white crystalline powder.

**Why the Correct Answer is Right**
Bleaching powder is a strong disinfectant and oxidizing agent due to the presence of hypochlorite ions (ClO⁻). These ions are responsible for the antimicrobial and bleaching properties of bleaching powder. They work by releasing oxygen free radicals, which damage the cell membranes of microorganisms, ultimately leading to their death. The antimicrobial activity of bleaching powder makes it effective against a wide range of bacteria, viruses, and fungi.

**Why Each Wrong Option is Incorrect**
* **Option A:** Bleaching powder is indeed used as a disinfectant in water treatment, so this option is correct and should not be the exception.
* **Option B:** Bleaching powder is indeed a strong oxidizing agent, so this option is also correct and should not be the exception.
* **Option C:** Bleaching powder is indeed used as a bleaching agent, so this option is correct and should not be the exception.

**Clinical Pearl / High-Yield Fact**
Bleaching powder is a strong irritant and can cause severe burns and eye damage if not handled properly. It is essential to wear protective gear, including gloves and goggles, when handling bleaching powder.

**Correct Answer: None**