The correct choice is (c) Hydrogen
For explanation I would say: Hydrogen gas has the highest calorific value of 150KJ/g among all. So, hydrogen gas is considered is considered to be an extremely good fuel. However, hydrogen gas is not used as a fuel in homes and industries. Reason is hydrogen is highly combustible and it burns with explosion when lighted, its transportation from place to place is very difficult, and the cost of production of hydrogen is very high.