Which of the following is defined as 'the percentage change in energy consumption to achieve 1% change in the national GDP in a specific country over time' ?

The correct answer is option 4.

Energy Elasticity is defined as the percentage change in energy consumption required to achieve a 1% change in a country's GDP over time. It indicates how energy consumption grows concerning economic growth.

Other options:

• Energy Efficiency: The ratio of useful output of a system to the input energy, focusing on reducing energy wastage.
• Energy Intensity: The amount of energy consumed per unit of GDP, indicating how energy-efficient an economy is.
• Energy Audit: A systematic process to analyze energy usage in a facility to improve efficiency and reduce consumption.