Correct Answer: (b) Gypsum
Solution:Gypsum is used to change to alkalinity of the soil and remove the salinity from it. It also requires one feet water for soil leaching. Gypsum gives nutrients to plants by providing sulphur and calcium where calcium helps in the absorption of nutrients in the roots, and sulphur improves crop yield. It has the ability to improve acid soils. It helps in treating aluminium toxicity. Adding lime or gypsum to dispersive soils decreases the sodium exchange percentage, reduces dispersion, and increases stable soil structure. Gypsum can be added to still water to separate the impurities. For example, adding gypsum to ponds so the dirt particles settle down without harming the aquatic life. It helps in treating orthopaedic and surgical casts. It can be consumed by humans and so it is present in food as additive ice cream, flour, blue cheese, white bread etc.
