**Core Concept**
The chlorination of water is a widely used disinfection process that involves the addition of chlorine to water to inactivate or kill pathogens. This process is crucial in preventing the spread of waterborne diseases. The main disinfecting action in chlorination is attributed to the generation of hypochlorous acid (HOCl), which is a potent antimicrobial agent.

**Why the Correct Answer is Right**
The disinfecting action of chlorination is primarily due to the formation of hypochlorous acid (HOCl), which is a strong oxidizing agent. HOCl is produced when chlorine reacts with water to form hypochlorous acid and hydrochloric acid. HOCl then reacts with the cell membranes of microorganisms, disrupting their structure and ultimately leading to their death. The efficacy of HOCl is attributed to its ability to covalently bind to cellular components, including proteins, lipids, and nucleic acids.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not specifically mention the formation of hypochlorous acid, which is the primary disinfecting agent in chlorination.
**Option B:** This option is incorrect as ozone is not the primary disinfecting agent in chlorination. While ozone is a strong oxidizing agent, its use in water disinfection is limited due to its instability and potential for adverse health effects.

**Clinical Pearl / High-Yield Fact**
One important consideration in chlorination is the pH of the water. Hypochlorous acid is more effective as a disinfectant at lower pH levels (acidic conditions). Therefore, it is essential to maintain a pH range of 6.5-7.5 during chlorination to ensure optimal disinfection.

**Correct Answer:** C.