The correct option is A Petroleum and Natural Gas
Fossil fuels are non-renewable sources of energy, that means they take millions of year to form fossil fuel, so we need to conserve them. Coal, petroleum and natural gas are the conventional sources of thermal power in India. They all are an example of fossil fuel. A large number of fossil fuels are burnt every day in power stations to
heat water to produce steam which further runs the turbine to
generate electricity. The term thermal
power plant is used since fuel is burnt to produce heat energy which is
converted into electrical energy.