Method of application of Biofertilizer is

Correct option is D

Biofertilizers can be applied using different methods depending on crop type and cultivation practices. They are commonly applied through seed treatment, soil application, and seedling root dip methods. Thus, all the listed methods are valid for the application of biofertilizers.
Information booster: Biofertilizers contain beneficial microorganisms that enhance nutrient availability to plants. They improve soil fertility and microbial activity without harming the environment. Common biofertilizers include Rhizobium, Azotobacter, Azospirillum, and phosphate solubilizing bacteria. Regular use of biofertilizers supports sustainable and eco-friendly agricultural production systems.
Why other options are incorrect: (a) Seed treatment alone does not cover all possible application methods. (b) Soil treatment is only one of the several methods available. (c) Seedling treatment is also a single method and not the complete answer.