**Core Concept**
Blood spills in the operation theatre pose a significant risk of infection transmission due to the presence of bloodborne pathogens. Effective cleaning and disinfection are crucial to prevent the spread of infection and maintain a sterile environment.

**Why the Correct Answer is Right**
The correct answer is a combination of hydrogen peroxide and sodium hydroxide. This mixture is effective in breaking down the hemoglobin in blood, thereby inactivating bloodborne pathogens such as HIV and hepatitis viruses. The hydrogen peroxide helps to oxidize the hemoglobin, while the sodium hydroxide acts as a surfactant to emulsify and break down the blood.

**Why Each Wrong Option is Incorrect**
**Option A:** Water alone is not sufficient to inactivate bloodborne pathogens and may even spread the infection.
**Option B:** Bleach is a strong disinfectant, but it requires a 1:10 dilution with water and is not specifically indicated for blood spills.
**Option C:** Normal saline is isotonic with blood and may not effectively break down the hemoglobin, allowing pathogens to remain viable.

**Clinical Pearl / High-Yield Fact**
When cleaning blood spills, it is essential to use a mixture of hydrogen peroxide and sodium hydroxide to effectively inactivate bloodborne pathogens. This is a critical step in maintaining a sterile environment in the operation theatre and preventing the transmission of infections.

**Correct Answer: C. Bleach is not the best option here. Normal saline is not isotonic with blood; it is isotonic with human blood serum. The correct answer is indeed a mixture of hydrogen peroxide and sodium hydroxide.