Which elements does an NPK fertilizer contain?
A) Nickel, phosphorus, potassium
B) Nickel, potassium, calcium
C) Nitrogen, phosphorus, potassium
D) Nitrogen, potassium, calcium

Hint: Most compound fertilizers contain three basic elements which are essential for the growth of plants. These elements help plants grow in different ways.

Complete answer:
NPK stands for Nitrogen (N), Phosphorus (P) and Potassium (K). Elements which are present in NPK fertilizer. Nitrogen, Phosphorus and Potassium or NPK are the “Big 3” primary nutrients which are used in commercial fertilizers. Of the three elements, nitrogen is considered to be the most important nutrient. Plants require nitrogen the most and hence they absorb it the most than any other element Nitrogen is an essential element is the formation of proteins, proteins further helps in tissue formation and growth of plants Phosphorus is another useful element for the plant which helps in the process of photosynthesis. Phosphorus is extracted from phosphorus rock. Potassium is one of the key nutrients. It helps in building the plant's abilities to resist disease. It helps to protect the plants from extreme weathers and helps in increasing yield and overall quality.

Thus, option (C) is the correct option.

Note: Students should note that there are 17 essential elements which are needed by plants to grow. Of these 17, 14 are absorbed by plants through the soil while the remaining three comes from air.