The correct answer is A. chemical fertilizers and pesticides.
Organic farming is a method of farming in which crops are cultivated in such a way to keep the soil alive and in good health by using organic waste of crop, animal and farm waste and aquatic waste. Other biological materials such as beneficial microbes are added to the crop field which release nutrients to the crops. Use of chemical fertilizers and pesticides should be limited as these are non-biodegradable and cause harm to the ecosystem and soil.