The correct option is A Does not contain chemicals
- Cow dung is obtained by the decomposition of animal excreta. Adding it is a natural way of increasing soil fertility and in turn, increasing the chances of growing crops.
- Fertilisers are artificially obtained and made up of chemicals. Excessive use of fertilisers kills the micro-organisms present in the soil. This causes soil pollution. When this soil reaches lakes and rivers, it causes water pollution as well.