Which of the following is true about biofuels? a. They are made from plant materials and animal fats. b. They are made by directly harnessing energy from the sun. c. They use energy from water. d. They use energy from the Earth’s core.

Answer is option A.

They are made from plant materials and animal fats.

Explanation:

The fuels produced directly or indirectly from biomass (organic material) which contains plant or algae materials such as grass, wood, charcoal, agricultural wastes, crops, etc and animal waste such as animal dung are known as biofuels. Solid, liquid and gaseous biofuels are available.

In primary biofuels, an unprocessed form of organic materials is used. They are used for cooking, heating, electricity production, etc. Examples include fuelwood, pellets, wood chips, etc.

In secondary biofuels, processed forms of biomass or organic materials are used. They are used in vehicles and industrial processes. Examples include liquid biofuels such as biodiesel and ethanol.  Biodiesel is produced by combining alcohol with vegetable oil or animal fat. Ethanol is a type of alcohol produced from biomass containing sugar or starch (sugar cane, sugar beet, wheat, corn, maize, etc) by using the processes of fermentation and distillation.

The liquid biofuels such as ethanol and biodiesel are referred to as first-generation biofuels. Second-generation biofuels refer to liquid fuels produced from the processing of certain components from plant matter such as cellulose, hemicellulose, and lignin.

Biofuel is a renewable energy source that can be replenished readily. It is very cost-effective and environmental friendly than fossil fuels such as natural gas, petroleum, coal, etc.

a

Explanation:

i just took the test. hope this helps !!