Which is the only country in the world to officially use the Gross National Happiness (GNH) as the measure of the country’s progress ?

Bhutan

The correct answer is Option 3: Bhutan

NCERT:"Bhutan is the only country in the world to officially proclaim the Gross National Happiness (GNH) as the measure of the country’s progress. Material progress and technological developments are approached more cautiously taking into consideration the possible harm they might bring to the environment or the other aspects of cultural and spiritual life of the Bhutanese. This simply means material progress cannot come at the cost of happiness. GNH encourages us to think of the spiritual, non-material and qualitative aspects of development".