The correct answer is option 3 - Use of synthetic fertilizers. Organic farming is known for its emphasis on natural and sustainable methods of agriculture. It involves the non-use of chemical fertilizers and pesticides, ensuring that crops are grown without harmful chemicals. Option 2 states that organic farming nurtures the soil for future use by maintaining micro-organisms. This is a common practice in organic farming, as healthy soil is crucial for sustainable agriculture. Option 4 states that organic farming involves very less energy consumption, which is also true. Organic farming often utilizes practices such as crop rotation and integrated pest management, which reduce the need for energy-intensive methods. However, option 3 is incorrect because the use of synthetic fertilizers goes against the principles of organic farming, which focuses on natural and organic fertilizers.