LPG is a fossil fuel which contains low carbon. It is a fossil fuel that does not occur during isolation. LPG is found naturally in combination with other hydrocarbons, crude oil, and natural gas. LPG is produced during natural gas processing and oil refining process.
Coal and Natural gas are also the fossil fuels and are obtained from earth crust.
Biogas is a mixture of methane ,carbon dioxide ,hydrogen and hydrogen sulphide. it is produced by anaerobic degradation of animal waste such as cow dunk in presence of water.
Hence options C is correct.