Ideal NPK ratio for Indian soils is______? 

As we have discussed, not all of the nutrients needed for the growth of different crops may be present in the soil. We also know that a total of six nutrients—carbon, hydrogen, oxygen, nitrogen, phosphorus, and potassium—are essential for plants to obtain from the soil. As a result, fertilisers are used to add nutrients from the outside to soil that lacks them.
The NPK ratio on these fertilisers' labels informs the consumer of the products' nitrogen, phosphorus, and potassium contents. In Indian soils, the NPK ratio is roughly 4:1:1. These values are present in proportion to their weight in fertilisers as a percentage.

The nitrogen is useful for the plants because they use it to promote flowering, fruit bearing, and the growth of leaves. The formation of roots, seeds, fruits, and flowers require phosphorus, and we also need potassium, which, as we all know, promotes a plant's general growth and increases its ability to withstand harsh environmental circumstances.

Hence, option B is correct.