Correct Answer - Option 3 : Proton exchange membrane fuel cell (PEMFC)
Concept:
DMFCs are limited in the power they can produce, but can still store a high energy content in a small space so it is used for consumer goods such as mobile phones, digital cameras or laptops.
Alkaline fuel cells (AFC) consume hydrogen and pure oxygen producing potable water, heat, and electricity. They are among the most efficient fuel cells, having the potential to reach 70% of power generation efficiency so it is used for space programme. Ex. Rockets, Submarines etc.
Proton-exchange membrane fuel cells is also known as polymer electrolyte membrane fuel cells (PEMFC), are a type of fuel cell being developed mainly for transport applications, as well as for stationary fuel-cell applications and portable fuel-cell applications.
SOFCs are well suited to stationary power generation for homes and businesses. Their high temperatures make them particularly efficient for Combined Heat and Power (CHP) systems, as waste heat can be put to good use for heating and cooling.
Hence from the above explanation we can see that option 3 is the correct answer since they are used for transport applications.
