The correct option is Health.
Explanation
The Human Development Index (HDI) is a composite index published by the United Nations Development Programme (UNDP). It assesses the average achievement of a country in three basic dimensions of human development.
Analysis of HDI Dimensions:
The HDI tracks progress based on three specific dimensions and their corresponding indicators:
- Long and healthy life (Health): This dimension is measured by Life Expectancy at Birth. It reflects the ability of the population to live a long life free from illness and premature death.
- Knowledge (Education): This dimension is measured by two indicators: Mean years of schooling for adults aged 25 years and more, and Expected years of schooling for children of school-entering age.
- A decent standard of living (Access to resources): This dimension is measured by Gross National Income (GNI) per capita based on purchasing power parity (PPP).
Therefore, 'Life Expectancy at Birth' is the specific indicator used to measure the health dimension of the HDI.
Key Takeaway:
The three dimensions of HDI are Health (Life Expectancy), Education (Mean and Expected Years of Schooling), and Standard of Living (GNI per capita).