Biofuel is a fuel that is produced from biomass (animal waste or plant/ algae material). Biofuel can be used as a fuel for vehicles and it can also be used as a diesel additive to minimize vehicle emissions. Biofuel is a source of renewable energy as it can be replenished readily. Types of biofuels are biodiesel, ethanol and biogas.
The answer is c. Wind won't power a car, and neither will heat or water. However, biofuel which is fuel made from living matter would power a car. :) hope this helps.
Always 10% of the energy is passed on to the next trophic level and 90% is lost... mostly heat: so if the producer has 500 units of energy then the primary consumer has 10% fromm 500 = so 50 units of energy is passed on to the next trophic level.