Which statement among the following is true?

On the basis of supply, the sources of energy are classified into renewable and non-renewable energy sources. And on the basis of how long we have been using different sources of energy, they are classified into conventional and non-conventional sources of energy. With regard to these four categories of energy sources, answer the following question:

Which among the following is a conventional source of energy?

Biomass is the organic matter like dead plants and animal waste from which we can get energy. Biomass which we have been using since long, include wood and cow-dung. But there are some major disadvantages related to their use due to which wood and cow-dung are now converted into charcoal and biogas respectively. With regard to the above information, answer the following question:

Wood can be converted to charcoal by

Biomass is the organic matter like dead plants and animal waste from which we can get energy. Biomass which we have been using since long, include wood and cow-dung. But there are some major disadvantages related to their use due to which wood and cow-dung are now converted into charcoal and biogas respectively. With regard to the above information, answer the following question:

Cow-dung is used to prepare biogas by

Biomass is the organic matter like dead plants and animal waste from which we can get energy. Biomass which we have been using since long, include wood and cow-dung. But there are some major disadvantages related to their use due to which wood and cow-dung are now converted into charcoal and biogas respectively. With regard to the above information, answer the following question:

For producing biogas, it needs :

Match the items in Column I to the items in Column II.