Which among the following statement about biofertilizers are correct?1. Azotobacter is one of the nitrogen fixing bacteria used as a biofertilizer.2. They have to be applied to the leaves of the plant only.3. They alter the chemical composition of the soil.4. They can be used along with organic fertilizers.Select the correct answer using the code given below

• A. 1 and 4
• B. 1, 2 and 4
• C. 2 and 3
• D. 1, 2, 3 and 4