Many scientists endeavor to find new technology which will create clean fuels. cell usage promises a pollution-free alternative to using fossil fuels. the cells make water by combining hydrogen and oxygen, which generates electricity.

Hydrogen fuel cell

Hydrogen is a clean fuel. When hydrogen is consumed in a fuel cell, produces water, electricity and heat. Hydrogen and fuel cells can provide energy for use in diverse applications, including distributed or combined-heat-and-power; backup power, systems for storing and enabling renewable energy, additional power help for trucks, aircraft, rail, and ships; specialty vehicles, passenger and freight vehicles including cars, trucks, and buses.

the correct answer is option b

behavioral response need communication and thus co-ordination at several levels such as interaction among cells, organ system and the entire organism.

behavioral response produces both internal and environmental stimulus.

emerging idea only occurs as a raw idea that could appear out of nowhere. meanwhile, to reach scientific consensus , that idea must be structured and tested over and over again through various experiments. the scientific consensus transforms the raw idea into idea that is more reliable through the process of scientific elimination.