Which one of the following is NOT an example of bio-mass energy source?

1. A

   Coal

   Coal claims to be a fossilized form of biomass derived from ancient plant matter subjected to heat and pressure. It is not the key because coal is indeed considered a biomass-derived fossil fuel source.

2. B

   Nuclear energy

   Nuclear energy claims to be derived from atomic reactions involving radioactive elements like uranium and thorium. This is the official key because nuclear energy originates from nuclear fission or fusion rather than from organic plant or animal biomass.

3. C

   Gobar (Dung)

   Gobar (Dung) claims to be animal waste utilized directly as fuel or for biogas production through anaerobic digestion. It is not the key because dung is a classic organic biomass energy source.

4. D

   Wood

   Wood claims to be a traditional renewable fuel sourced from trees and woody plants. It is not the key because wood is one of the most common forms of biomass energy.

Summary. Official key is (b) Nuclear energy. The question asks to identify which option does not constitute a biomass energy source among the given choices. Coal, gobar, and wood are all derived from organic matter and living organisms, making them biomass-related fuels. Nuclear energy relies on atomic reactions and radioactive minerals rather than organic biological material. Therefore, only option (b) correctly represents a non-biomass energy source.