What role does a sanitizer play in water treatment?

A sanitizer plays a crucial role in water treatment primarily to kill or inactivate pathogenic microorganisms. This function is essential for ensuring that the water is safe for consumption and meets health standards. Sanitizers, such as chlorine, chloramine, or ozone, are added to water systems to eliminate or reduce harmful bacteria, viruses, and protozoa that can cause waterborne diseases. The effectiveness of a sanitizer is measured by its ability to reduce the microbial load in the water, which is vital for public health.

While enhancing taste and odor, improving aesthetic quality, and softening water are important aspects of water treatment, they do not directly address the primary purpose of making water microbiologically safe. The addition of sanitizers specifically targets pathogens, making option C the most appropriate choice in the context of water treatment operations focused on health and safety.