The correct option is D <!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> Social life
The Human Happiness Index considers nine factors to measure development. They are health, standard of living, conservation of nature and biodiversity, social life and neighbour relations, good governance, cultural diversity, education, effective use of time, and mental health. On the other hand, the infant mortality rate is a tool of the Physical Quality of Life Index and is not related to a person's happiness.