Biomass based energy can be obtained from:
(A) Direct burning of wood, agricultural residue, etc.
(B) Biomass may be converted into some other form of fuel which can release energy.
(C) Bacterial decomposition of organic matters like cow dung, agricultural wastes, human excreta etc. in presence of water in absence of air, a mixture of $ C{H_4} $ , $ C{O_2} $ , $ {H_2} $ , $ {H_2}S $ , etc.
(D) Burning of industrial waste.

Hint: Here, it has been asked that biomass energy is the basis of what from the given options as the answer. For this question to be answered we must understand what this biomass means and then find out its characteristics and identify the correct option.

Complete step by step answer:
Now, let us first understand the meaning of biomass energy.
Biomass energy is the energy generated from things that once lived such as wood, dry vegetation, residues of crops, plants in aquatic bodies, and biodegradable waste. When plants lived, they used a lot of energy from the sun to make their own food and this food is stored in the plants in a form of chemical energy. In other words, biomass energy is the result of decomposition of these biodegradable wastes.
Thus, we concluded that the correct answer for this question is:
Direct burning of wood, agricultural residue, etc. can produce biomass fuels. Biomass may be converted into some other form of fuel which can release energy. Bacterial decomposition of organic matters like cow dung, agricultural wastes, human excreta etc. in presence of water in absence of air, a mixture of $ C{H_4} $ , $ C{O_2} $ , $ {H_2} $ , $ {H_2}S $ , etc.
The correct answer is options A, B and C.

Note:
Biomass itself is the whole meaning of the biomass energy since this is the energy formed by the decomposition or burning of the biodegradable waste in the atmosphere. Industrial waste burning cannot be used to produce this energy since this waste is purely chemical containing and is harmful for nature.