Solution:
Concept: For the growth and development of plants, nitrogen is a crucial component. Both the vegetative and reproductive phases of a plant's growth call for it. Different sections of the plant can exhibit nitrogen shortage. So, nitrogenous fertiliser is applied to plants to completely make up for this shortage. A nitrogen-based fertiliser is one that contains nitrogen. Along with other organic substances, it contains the element nitrogen.1) Sugar-Phosphate: This particular type of fertiliser has sugar and phosphate as ingredients. Therefore, this is not the right response.
2) The structure of urea is as follows:
Two 
units are present in the urea molecule. As a result, the plants will receive nitrogen from this, and urea can then be used as nitrogenous fertiliser.3) Potassium sulphate: This fertiliser has ions of sulphate and potassium metal. Therefore, it is not fertiliser dependent on nitrogen. Consequently, choice (3) is not the appropriate response.
4) Potassium chloride: Since it also contains chloride and potassium ions, it is not a nitrogen-based fertiliser. Thus, even this is an incorrect choice.
Hence, the correct answer is option 2.
