The answer is E. Potash.
Manure, nitrogen, ammonia, and urea are all fertilizers. Potash is a mineral that is used to make fertilizer, but it is not a fertilizer itself.
Manure is a substance produced by the decomposition of animal excreta and other organic matter, such as plant material. It is used as a fertilizer to improve soil fertility and crop yields.
Nitrogen is an essential element for plant growth. It is found in proteins, nucleic acids, and other important molecules. Nitrogen can be added to soil in the form of fertilizer, manure, or compost.
Ammonia is a gas that is produced when nitrogen and hydrogen combine. It is used as a fertilizer and as a raw material in the production of other chemicals.
Urea is a solid that is produced when ammonia and carbon dioxide combine. It is used as a fertilizer and as a raw material in the production of other chemicals.
Potash is a mineral that is found in rocks and soil. It is a source of potassium, which is an essential element for plant growth. Potassium is found in proteins, nucleic acids, and other important molecules. It helps plants to regulate water uptake, produce energy, and resist disease.