Ans: b) oil
Energy resources can be broadly classified into two categories: renewable and non-renewable
Renewable sources of energy are those which can be constantly replenished like solar energy, wind, hydrothermal etc
Non-renewable sources are a finite resource and cannot be replenished. This include fossil fuels like coil, oil and natural gas as well as nuclear energy. Among the non-renewable sources, oil accounts for 95% of consumption for transportation.