Which of the following is a form of chlorine?

Liquid Sodium Hypochlorite is a form of chlorine because it contains chlorine in a dissolved state and is commonly used as a disinfectant in drinking water treatment. Sodium hypochlorite is the chemical compound that produces chlorine when it dissociates in water. This substance is utilized widely for its strong oxidizing and disinfecting properties, making it effective in eliminating pathogens in water sources.

Chlorinated water refers to water that has been treated with chlorine but does not represent a physical form of chlorine itself. Calcium Sodium Carbonate is a combination of calcium, sodium, carbon, and oxygen, having no direct relation to chlorine. Carbon Dioxide is a completely different chemical compound composed of carbon and oxygen, with no chlorine content.