**Core Concept**
Bleaching powder is a widely used disinfectant for various applications, including water treatment and surface disinfection. Its effectiveness in disinfecting urine and feces is crucial in preventing the spread of infectious diseases. The concentration of bleaching powder used is critical to ensure effective disinfection while minimizing the risk of toxicity.

**Why the Correct Answer is Right**
The correct concentration of bleaching powder for disinfecting urine and feces is 5 grams per liter (g/L) or 5000 parts per million (ppm). This concentration is effective against a broad spectrum of microorganisms, including bacteria, viruses, and fungi. The hypochlorous acid (HOCl) produced by the reaction of bleaching powder with water is the primary disinfectant responsible for its antimicrobial activity. HOCl denatures proteins, disrupts cell membranes, and inhibits enzymatic activity, ultimately leading to the death of microorganisms.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not specified, so we cannot provide an explanation.
**Option B:** Using a lower concentration of bleaching powder, such as 1 g/L, may not be effective in disinfecting urine and feces, potentially leading to the survival of microorganisms.
**Option C:** Using a higher concentration of bleaching powder, such as 10 g/L, may increase the risk of toxicity and damage to surfaces or equipment.

**Clinical Pearl / High-Yield Fact**
When using bleaching powder for disinfection, it is essential to follow the recommended concentration and ensure proper mixing with water to avoid creating a solution that is too concentrated or too dilute.

**Correct Answer: C. 10 g/L.**