ANS:D - all of these.

1. Indore method of composting involves decomposition under aerobic conditions: The Indore method of composting is a traditional method that involves the decomposition of organic waste materials under aerobic (oxygen-rich) conditions. This method relies on frequent turning and mixing of the compost pile to ensure adequate aeration and oxygen supply for the microorganisms responsible for decomposition. Aerobic composting processes are typically faster and result in the production of high-quality compost.
2. Bangalore method of composting involves decomposing under anaerobic conditions: The Bangalore method of composting, also known as the pit composting method, involves the decomposition of organic waste materials under anaerobic (oxygen-depleted) conditions. This method entails burying organic waste in pits or trenches where anaerobic microorganisms break down the waste in the absence of oxygen. While anaerobic composting is slower compared to aerobic methods, it can still effectively decompose organic matter and produce compost.
3. Fully stabilised refuse by the Bangalore method of composting is a powdery mass called humus: In the Bangalore method of composting, the organic waste undergoes decomposition over an extended period, resulting in the production of fully stabilized compost. The end product of the Bangalore method is indeed a powdery, dark-colored mass called humus. Humus is rich in organic matter and nutrients, making it a valuable soil conditioner and fertilizer. It helps improve soil structure, moisture retention, and nutrient availability, thereby enhancing soil fertility and promoting plant growth.