Which of the following salts plays a crucial role in fertiliser industry?

Calcium chloride behaves as an ionic halide and is solid at room temperature. Common applications include brine for refrigeration plants, ice and dust control on roads and desiccation. Potassium carbonate is a white salt, which forms a strongly alkaline solution. It is used in the production of soap and glass. Potassium chlorate is a white crystalline substance. It is the most common chlorate in industrial use. It is used as an oxidising agent as a disinfectant in safety matches, explosives and fireworks. Potassium chloride (KCl) is a metal halide salt composed of potassium and chlorine. In its pure state, it is odourless and has a white or colourless vitreous crystal appearance. The majority of potassium chloride produced is used for making fertilisers as the growth of many plants is limited by their potassium intake.